trilogy practical revision guide · gcse trilogy required practical activity: osmosis required...

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TrilogyRequiredPracticalRevisionGuide–AlsagerSchoolScienceDepartment

RequiredPractical Page

Usealightmicroscopetoobserve,drawandlabelaselectionofplantandanimalcells.

Amagnificationscalemustbeincluded.

https://www.youtube.com/watch?v=XKPdnE6BGew

https://www.youtube.com/watch?v=DyL6s15WeqY

https://www.youtube.com/watch?v=GXqrpb91JPg

https://www.youtube.com/watch?v=J3HfSss5YPs

6-11

Investigatetheeffectofarangeofconcentrationsofsaltorsugarsolutionsonthemassofplanttissue.

https://www.youtube.com/watch?v=oieXYuQm_xE

https://www.youtube.com/watch?v=aA_UvVeQbww&t=32s

12–18

Usequalitativereagentstotestforarangeofcarbohydrates,lipidsandproteins.

Toinclude:

Benedict’stestforsugars;

iodinetestforstarch;

Biuretreagentforprotein.

https://www.youtube.com/watch?v=sLP8dcnWnJg

https://www.youtube.com/watch?v=81SpohOUHjA

28-30

InvestigatetheeffectofpHontherateofreactionofamylaseenzyme. 19–27

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Studentsshoulduseacontinuoussamplingtechniquetodeterminethetimetakentocompletelydigest

astarchsolutionatarangeofpHvalues.Iodinereagentistobeusedtotestforstarchevery30seconds.Temperaturemustbecontrolledbyuseofawaterbathorelectricheater.

https://www.youtube.com/watch?v=7wJItifm9Ws

https://www.youtube.com/watch?v=8Yqbu56ImXk&t=11s

Investigatetheeffectoflightintensityontherateofphotosynthesisusinganaquaticorganismsuchaspondweed.

https://www.youtube.com/watch?v=yg8vqsBOFMw&t=6s

https://www.youtube.com/watch?v=6xEEDZAiTME

30–39

Planandcarryoutaninvestigationintotheeffectofafactoronhumanreactiontime.

https://www.youtube.com/watch?v=81lPJtAp5Sc

https://www.youtube.com/watch?v=3XM-4Qavh5k

40–50

Measurethepopulationsizeofacommonspeciesinahabitat.Usesamplingtechniquestoinvestigatetheeffectofafactoronthedistributionofthisspecies.

https://www.youtube.com/watch?v=UDp3I07Wcrg

https://www.youtube.com/watch?v=lKyj7gEAAS8&t=53s

51–62

Preparationofapure,drysampleofasolublesaltfromaninsolubleoxideorcarbonate,usingaBunsenburnertoheatdiluteacidandawaterbathorelectricheatertoevaporatethesolution.

https://www.youtube.com/watch?v=qIOMlwBoe_4

https://www.youtube.com/watch?v=B1oS1_vDmUk

63-72

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Investigatewhathappenswhenaqueoussolutionsareelectrolysedusinginertelectrodes.Thisshould

beaninvestigationinvolvingdevelopingahypothesis.

https://www.youtube.com/watch?v=pW8oBf-UCWQ

https://www.youtube.com/watch?v=KvW-g1FQV9E

72–82

Investigatethevariablesthataffecttemperaturechangesinreactingsolutionssuchas,egacidplus

metals,acidpluscarbonates,neutralisations,displacementofmetals.

https://www.youtube.com/watch?v=xO7QL0S90e8

https://www.youtube.com/watch?v=htiSN2qGuGc

83–89

Investigatehowchangesinconcentrationaffecttheratesofreactionsbyamethodinvolvingmeasuringthevolumeofagasproducedandamethodinvolvingachangeincolourorturbidity.

Thisshouldbeaninvestigationinvolvingdevelopingahypothesis.

https://www.youtube.com/watch?v=WlitM81qGqE

https://www.youtube.com/watch?v=wJXoUrBV6rk&index=3&list=PLDB8KPHmXFyc14g6QuLodbPgddhkYGA4o

89–106

Investigatehowpaperchromatographycanbeusedtoseparateandtellthedifferencebetweencolouredsubstances.

StudentsshouldcalculateRfvalues.

https://www.youtube.com/watch?v=-XCPPB-sBFU

https://www.youtube.com/watch?v=kxrjvLvbY28

106–113

Analysisandpurificationofwatersamplesfromdifferentsources,includingpH,dissolvedsolidsanddistillation.

https://www.youtube.com/watch?v=N0f73tbGCRE

113-116

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Aninvestigationtodeterminethespecificheatcapacityofoneormorematerials.

Theinvestigationwillinvolvelinkingthedecreaseofoneenergystore(orworkdone)totheincreaseintemperatureand

subsequentincreaseinthermalenergystored.

https://www.youtube.com/watch?v=jW2ANwnfsUY

https://www.youtube.com/watch?v=ZYSdBU0pLvc

116–122

Usecircuitdiagramstosetupandcheckappropriatecircuitstoinvestigatethefactorsaffectingtheresistanceofelectricalcircuits.

Thisshouldinclude:

••thelengthofawireatconstanttemperature

••combinationsofresistorsinseriesandparallel.

https://www.youtube.com/watch?v=ZJKmovo-MoM

https://www.youtube.com/watch?v=m_3JrA-sDEg

https://www.youtube.com/watch?v=XSukRnxGy5c

123–128

UsecircuitdiagramstoconstructappropriatecircuitstoinvestigatetheI–Vcharacteristicsofvarietyof

circuitelementsincluding:

afilamentlamp;

adiode;

aresistoratconstanttemperature.

https://www.youtube.com/watch?v=1DI0By1Osrc

https://www.youtube.com/watch?v=1QtI15E-GMU

128–138

Useappropriateapparatustomakeandrecordthemeasurementsneededtodeterminethedensitiesofregularandirregularsolidobjectsandliquids.Volumeshouldbedeterminedfromthedimensionsofregularlyshapedobjectsandbya

138–141

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displacementtechniqueforirregularlyshapedobjects.Dimensionstobemeasuredusingappropriateapparatussuchasaruler,micrometerorVerniercallipers.

https://www.youtube.com/watch?v=F7uto-YfSRc

https://www.youtube.com/watch?v=lh4W-cXcsBQ

https://www.youtube.com/watch?v=Ypg6mRbEhWs

Investigatetherelationshipbetweenforceandextensionforaspring.

https://www.youtube.com/watch?v=XoukVo6MR40

https://www.youtube.com/watch?v=QQCJeAqBumE

142–149

Investigatetheeffectofvaryingtheforceontheaccelerationofanobjectofconstantmassandtheeffectofvaryingthemassofanobjectontheaccelerationproducedbyaconstantforce.

https://www.youtube.com/watch?v=gaKXmWdmeVQ&list=PLM2vhNffrPZf2tUarsQounK6plAUim2z9

https://www.youtube.com/watch?v=nRaJd59ooIE

150–154

Makeobservationstoidentifythesuitabilityofapparatustomeasurethefrequency,wavelengthandspeedofwavesinarippletankandwavesinasolidandtakeappropriatemeasurements.

https://www.youtube.com/watch?v=kgL-hOBvQcc

https://www.youtube.com/watch?v=HANMKi6-Guk

154–159

Investigatehowtheamountofinfraredradiationabsorbedorradiatedbyasurfacedependsonthenatureofthatsurface.

https://www.youtube.com/watch?v=ClRrU6JuBOc

https://www.youtube.com/watch?v=4Pz8xcEQtMU

160–170

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GCSETrilogyrequiredpracticalactivity:Microscopy

Requiredpracticalactivity Apparatusandtechniques

Usealightmicroscopetoobserve,drawandlabelaselectionofplantandanimalcells.Amagnificationscalemustbeincluded.

AT1,AT7

Usingalightmicroscopetoobserve,drawandlabelcellsinanonionskin

Prepareamicroscopeslidetoshowthecontentsofcellsfromonionskin.

Useanopticalmicroscopetoobserveanddrawtheonioncells.Youwillalsoneedtoidentifystructureswithinthecells.

Method

Youareprovidedwiththefollowing:

• asmallpieceofonion

• aknife

• awhitetile

• forceps

• amicroscopeslide

• acoverslip

• amicroscope

• iodinesolutioninadroppingbottle

• prepared animal and plant cells

Readtheseinstructionscarefullybeforeyoustartwork.1. Useadroppingpipettetoputonedropofwaterontoamicroscopeslide.2. Separateoneofthethinlayersoftheonion.3. Peeloffathinlayerofepidermaltissuefromtheinnersurface.4. Useforcepstoputthisthinlayerontothedropofwaterthatyouhaveplacedonthemicroscopeslide.5. Makesurethatthelayerofonioncellsisflatontheslide.6. Puttwodropsofiodinesolutionontotheoniontissue.7. Carefullyloweracoverslipontotheslide.Dothisby:

• placing one edge of the coverslip on the slide • use the forceps to lower the other edge onto the slide.

8. Theremaybesomeliquidaroundtheedgeofthecoverslip.Useapieceofpapertosoakthisliquidup.9. Puttheslideonthemicroscopestage.

Usingthemicroscopetolookatanimalandplantcells

Thediagramshowsatypicalmicroscope.

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Thismicroscopehasamirrortoreflectlightupthroughtheslide.Somemicroscopeshaveabuilt-inlightinsteadofamirror.

10. Usethelowestpowerobjectivelens.Turnthenosepiecetodothis.11. Theendoftheobjectivelensneedstoalmosttouchtheslide.Dothisbyturningthecoarseadjustmentknob.

Lookfromtheside(notthroughtheeyepiece)whendoingthis.12. Nowlookingthroughtheeyepiece,turnthecoarseadjustmentknobinthedirectiontoincreasethedistance

betweentheobjectivelensandtheslide.Dothisuntilthecellscomeintofocus.13. Nowrotatethenosepiecetouseahigherpowerobjectivelens.14. Slightlyrotatethefineadjustmentknobtobringthecellsintoaclearfocusandusethehigh-powerobjectiveto

lookatthecells.15. Makeaclear,labelleddrawingofsomeofthesecells.Makesurethatyoudrawandlabelanycomponentparts

ofthecell.16. Writethemagnificationunderneathyourdrawing.

Questions1. Explainwhyiodineisaddedtotheslide

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2. LabelpartsA–Cofthediagrambelow

Q1.Figure 1 shows a human cheek cell viewed under a light microscope.

Figure 1

© Ed Reschke/Photolibrary/Getty Images

(a) Label the nucleus and cell membrane on Figure 1. (2)

(b) Cheek cells are a type of body cell.

Body cells grow through cell division.

What is the name of this type of cell division? Tick one box.

Differentiation

Mitosis

A

B

C

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Specialisation

(1)

(c) Ribosomes and mitochondria are not shown in Figure 1.

What type of microscope is needed to see ribosomes and mitochondria?

............................................................................................................................. (1)

(d) What is the advantage of using the type of microscope you named in part (c)?

Tick one box.

Cheaper

Higher magnification

Lower resolution

(1)

(e) The cheek cell in Figure 2 is magnified 250 times.

The width of the cell is shown by the line D to E.

Figure 2

Calculate the width of the cheek cell in micrometres (µm).

Complete the following steps.

Measure the width of the cell using a ruler .......................................... mm

Use the equation to work out the real width of the cell in mm:

real size = ............................................ mm

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Convert mm to µm ............................................. µm (3)

(f) A red blood cell is 8 µin diameter.

A bacterial cell is 40 times smaller.

Calculate the diameter of the bacterial cell.

Tick one box.

0.02 µm

0.2 µm

2.0 µm

20.0 µm

(1)

(Total 9 marks)

Q2.Living organisms are made of cells.

(a) Animal and plant cells have several parts. Each part has a different function.

Draw one line from each cell part to the correct function of that part.

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(3)

(b) The diagram below shows a cell from a plant leaf.

Which two parts in the diagram above are not found in an animal cell?

1 ....................................................................................................................

2 .................................................................................................................... (2)

(Total 5 marks)

GCSETrilogyrequiredpracticalactivity:Osmosis


Investigatetheeffectofarangeofconcentrationsofsaltorsugarsolutionsonthemassofplanttissue.

AT1,AT3,AT5

Investigatingosmosisinpotatotissue

Osmosisisthemovementofwaterthroughaselectivelypermeablemembrane.Thewatermovesfromanareaofhighconcentrationofwatertoanareaoflowerconcentrationofwater.

Planttissuescanbeusedtoinvestigateosmosis.Thisexperimentusespotato,butothertissuesuchassweetpotato,carrotorbeetrootcanbeused.

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Potatotissueiscutintoequalsizedcylinders.Thepotatotissueisleftovernightinsugarsolutionanddistilledwater.Thechangesinlengthandmasscanthenbeaccuratelycompared.

Method


• apotato

• acorkborerorpotatochipper/vegetablestickcutter

• aruler

• a10cm3measuringcylinder

• labels

• threeboilingtubes

• atesttuberack

• papertowels

• asharpknife

• awhitetile

• arangeofsugarsolutions

• distilledwater

• atop-panbalance. Read these instructions carefully before you start work. 1. Use a cork borer to cut five potato cylinders of the same diameter. 2. Trim the cylinders so that they are all the same length (about 3 cm). 3. Accurately measure and record the length and mass of each potato cylinder. 4. Measure 10 cm3 of the 1.0 M sugar solution and put into the first boiling tube. Label boiling tube as:

1.0. M sugar. 5. Repeat step 4 to produce the additional labelled boiling tubes containing solutions of 0.75 M, 0.5 M.

and 0.25 M. 6. Measure 10 cm3 of the distilled water and put into the fifth boiling tube. Label boiling tube as water. 7. Add one potato cylinder to each boiling tube. Make sure you know the length and mass of each potato

cylinder in each boiling tube. 8. Record the lengths and masses of each potato cylinder in a table such as the one below.

1.0Msugarsolution

0.75sugarsolution

0.5Msugarsolution

0.25Msugarsolution

Distilledwater

Initiallength(mm)

Finallength(mm)

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Changeinlength(mm)

Initialmass(g)

Finalmassin(g)

Changeinmassin(g)

9. Leave the potato cylinders in the boiling tubes overnight in the test tube rack. 10. Remove the cylinders from the boiling tubes and carefully blot them dry with the paper towels. 11. Re-measure the length and mass of each cylinder (make sure you know which is which). Record your measurements in the table. Then calculate the changes in length and mass of each

potato cylinder. 12. Plot a graph with:

• ‘Change in mass in g’ on the y-axis • ‘Concentration of sugar solution’ on the x-axis.

13. Plot another graph with:

• ‘Change in length in mm’ on the y-axis • ‘Concentration of sugar solution’ on the x-axis. Compare the two graphs that you have drawn.

Questions

1.Defineosmosis

2.Whatistheindependentvariable?

3.Whatistherangeoftheindependentvariableinthismethod?

4.Whatarethedependentvariables?

5.Giveatleast2controlvariables.

6.Whatwillhappentothemassandlengthofthepotatoinpurewater?Explainyouranswerintermsofosmosis.

Q1.Cells, tissues and organs are adapted to take in different substances and get rid of different substances.

The table shows the concentration of four ions outside cells and inside cells.

Ion Concentration

outside cells in mmol per dm3

Concentration inside cells in mmol per dm3

Sodium 140 9

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Potassium 7 138

Calcium 2 27

Chloride 118 3

(a) Use information from the table above to complete the following sentences.

Sodium ions will move into cells by the process

of .................................................................. .

Potassium ions will move into cells by the process

of .................................................................. . (2)

(b) Some students investigated the effect of the different concentrations of sugar in four drinks, A, B, C and D, on the movement of water across a partially permeable membrane.

The students:

• made four bags from artificial partially permeable membrane

• put equal volumes of 5% sugar solution in each bag

• weighed each bag containing the sugar solution

• placed one bag in each of the drinks, A, B, C and D

• after 20 minutes removed the bags containing the sugar solution and weighed them again.

The diagram below shows how they set up the investigation.

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(b) (i) The bag in drink A got heavier after 20 minutes.

Explain why.

...................................................................................................................

...................................................................................................................

...................................................................................................................

................................................................................................................... (3)

(ii) In which drink, A, B, C or D, would you expect the bag to show the smallest change in mass?

Tick () one box.

A

B

C

D

(1)

(iii) Explain why you think the bag you chose in part (b)(ii) would show the smallest change.

...................................................................................................................

...................................................................................................................

...................................................................................................................

................................................................................................................... (2)

(Total 8 marks)

Q2.A student investigated the effect of different sugar solutions on potato tissue.

This is the method used.

1. Add 30 cm3 of 0.8 mol dm−3 sugar solution to a boiling tube.

2. Repeat step 1 with equal volumes of 0.6, 0.4 and 0.2 mol dm−3 sugar solutions.

3. Use water to give a concentration of 0.0 mol dm−3.

4. Cut five cylinders of potato of equal size using a cork borer.

5. Weigh each potato cylinder and place one in each tube.

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6. Remove the potato cylinders from the solutions after 24 hours.

7. Dry each potato cylinder with a paper towel.

8. Reweigh the potato cylinders.

The table below shows the results.

Concentration of sugar

solution in mol dm−3

Starting mass in g

Final mass in g

Change of mass in g

Percentage (%) change

0.0 1.30 1.51 0.21 16.2

0.2 1.35 1.50 0.15 X

0.4 1.30 1.35 0.05 3.8

0.6 1.34 1.28 −0.06 −4.5

0.8 1.22 1.11 −0.11 −9.0

(a) Calculate the value of X in the table above.

.............................................................................................................................

.............................................................................................................................

Percentage change in mass = ........................................ % (2)

(b) Why did the student calculate the percentage change in mass as well as the change in grams?

.............................................................................................................................

............................................................................................................................. (1)

(c) Complete the graph using data from the table above.

• Choose a suitable scale and label for the x-axis.

• Plot the percentage (%) change in mass.

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• Draw a line of best fit.

(4)

(d) Use your graph to estimate the concentration of the solution inside the potato cells.

Concentration = ............................................... mol dm−3

(1)

(e) The results in the table above show the percentage change in mass of the potato cylinders.

Explain why the percentage change results are positive and negative.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

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.............................................................................................................................

............................................................................................................................. (3)

(f) Suggest two possible sources of error in the method given above.

1...........................................................................................................................

.............................................................................................................................

2...........................................................................................................................

............................................................................................................................. (2)

(Total 13 marks)

GCSETrilogyrequiredpracticalactivity:Enzymes


InvestigatetheeffectofpHontherateofreactionofamylaseenzyme.

StudentsshoulduseacontinuoussamplingtechniquetodeterminethetimetakentocompletelydigestastarchsolutionatarangeofpHvalues.Iodinereagentistobeusedtotestforstarchevery30seconds.

AT1,AT2,AT5,AT8

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Temperaturemustbecontrolledbyuseofawaterbathorelectricheater.

InvestigatingtheeffectofpHontheenzymeamylase

Theenzymeamylasecontrolsthebreakdownofstarchinourdigestivesystem.Weareabletosimulatedigestionusingsolutionsofstarchandamylaseintesttubes.Wecanalsodeterminetheoptimumconditionsrequired.

Thepresenceorabsenceofstarchcanbedeterminedusingiodinesolution.Inthisexperiment,wecanmeasurehowlongtheamylasetakestobreakdownthestarchatdifferentpHs.


• testtubes

• atesttuberack

• waterbath(electricalorBunsenburnerandbeakers)

• spottingtiles

• 5cm3measuringcylinder

• syringes

• astopclock

• starchsolution

• amylasesolution

• bufferedsolutionscoveringarangeofpH,eachwithalabelledsyringe/plasticpipette

• iodinesolution

• syringes.

1. Placeonedropofiodinesolutionintoeachdepressiononthespottingtile.2. PlacelabelledtesttubescontainingthebufferedpHsolutions,amylasesolutionandstarchsolutionsintothe

waterbath3. Allowthesolutionstoreach25°C4. Add2cm3ofoneofthebufferedsolutionstoatesttube.5. Usethesyringetoplace2cm3ofamylaseintothebufferedpHsolution.6. Useanothersyringetoadd2cm3ofstarchtotheamylase/buffersolution.7. Immediatelystartthestopclockandleaveitonthroughoutthetest.8. Mixusingaglassrod.9. After30seconds,removeonedropofthemixturewithaglassrod.

Placethisdroponthefirstdepressionofthespottingtilewiththeiodinesolution. The iodine solution should turn blue-black.

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10.Rinsetherod.

11.Usetheglassrodtoremoveonedropofthemixtureevery30seconds.Puteachdropontotheiodinesolutioninthenextdepressiononthespottingtile.Rinsetheglassrodwithwateraftereachdrop.Continueuntiltheiodinesolutionandtheamylase/buffer/starchmixtureremainorange.

12.RepeattheprocedurewithsolutionsofotherpHs

13.Recordyourresultsinatablesuchastheonehere.

pHofsolutionTimetakenforamylasetocompletelybreakdownthestarchin

seconds(s)

Questions 1. What is the independent variable in this investigation? 2. What is the dependent variable? 3. Temperature is an example of a control variable, what piece of equipment is used in this investigation to control the temperature? 4. What is the name of the enzyme in this reaction? 5. What is the name of the substrate in this reaction? 6. What is Iodine used for in this experiment?

Q1.Catalase is an enzyme.

Catalase controls the following reaction:

hydrogen peroxide water + oxygen

A student did an investigation on catalase activity.

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1. Put 1 cm3 hydrogen peroxide solution in a test tube.

2. Add 1 cm3 of catalase solution.

• Bubbles of oxygen are produced.

• Bubbles cause foam to rise up the tube.

3. Measure the maximum height of the foam.

The diagram below shows the experiment.

The experiment is carried out at 20 °C.

The table below shows some results from the investigation.

Temperature in °C

Maximum height of foam in cm

Test 1 Test 2 Test 3 Mean

10 1.3 1.1 0.9 1.1

20 0.0 3.3 3.1 3.2

30 5.2 5.0 5.3 5.2

40 4.2 3.5 4.4 4.0

50 2.1 1.9 2.3 2.1

60 0.0 0.0 0.0 0.0

(a) Why did the student carry out the experiment three times at each temperature?

Tick one box.

To make the experiment more accurate

To prove the experiment was correct

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To show the experiment was more repeatable

(1)

(b) The student thought one result was an anomaly.

Circle the anomaly in the table above. (1)

(c) What did the student do with the anomalous result?

.............................................................................................................................

............................................................................................................................. (1)

(d) Look at the table above.

What conclusion can be made as the temperature increases?

Tick one box.

Decreases the rate of reaction up to 30 °C

Decreases the rate of reaction up to 40 °C

Increases the rate of reaction up to 30 °C

Increases the rate of reaction up to 40 °C

(1)

(e) At which temperature was catalase denatured?

Tick one box.

10 °C

30 °C

40 °C

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60 °C

(1)

(f) The student thought the optimum temperature for catalase activity was between 30 °C and 40 °C.

How could the investigation be improved to find a more precise value for the optimum temperature?

Tick one box.

Do the experiment at 70 °C and 80 °C

Do the experiment at 30 °C, 35 °C and 40 °C

Use less hydrogen peroxide solution

Use more catalase solution

(1)

(g) Amylase is the enzyme that controls the breakdown of starch to glucose.

Describe how the student could investigate the effect of pH on the breakdown of starch by amylase.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (4)

(Total 10 marks)

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Q2.Catalase is an enzyme found in many different tissues in plants and animals.It speeds up the rate of the following reaction.

hydrogen peroxide water + oxygen

Figure 1 shows a 25-day-old broad bean seedling.

Some students investigated whether different parts of bean seedlings contained different amounts of catalase.

The students: • put hydrogen peroxide into five test tubes

• added a different part of a bean seedling to each tube

• recorded the results after half a minute.

If there was catalase in part of the seedling, oxygen gas was given off. When oxygen gas is given off, foam is produced in the tubes.

Figure 2 shows the results.

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The students made the following conclusions: • most parts of a bean seedling contain catalase

• the seed contains a lot of catalase

• stems and roots have quite a lot of catalase

• the leaves have a little bit of catalase

• the seed coat has hardly any catalase.

The students’ teacher said that the students needed to improve their investigation in order to make valid conclusions.

(a) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

Describe how you would carry out an investigation to compare the amounts of catalase in different parts of bean seedlings.

You should include details of how you would make sure your results give a valid comparison of the amounts of catalase.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

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........................................................................................................................ (6)

(b) Scientists investigated the effect of pH on the activity of the enzyme catalase in a fungus.

The table below shows the scientists’ results.

pH Enzyme activity in arbitrary units

Test 1 Test 2 Test 3 Test 4 Test 5 Mean

3.0 0 0 0 0 0 0

4.0 6 5 8 4 7 6

5.0 38 65 41 42 39

5.5 80 86 82 84 88 84

6.0 100 99 96 103 102 100

6.5 94 92 90 93 91 92

7.0 61 63 61 62 63 62

8.0 22 22 21 24 21 22

(i) Calculate the mean enzyme activity at pH 5.0.

...............................................................................................................

...............................................................................................................

Mean = ......................... arbitrary units (2)

(ii) On the graph paper in Figure 3, draw a graph to show the scientists’ results.

Remember to: • add a label to the vertical axis

• plot the mean values of enzyme activity

• draw a line of best fit.

Figure 3

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(4)

(iii) At what pH does the enzyme work best?

........................................ (1)

(iv) Predict the activity of the enzyme at pH 9.0.

........................................ arbitrary units (1)

(v) Suggest why the enzyme’s activity at pH 3.0 is zero.

...............................................................................................................

............................................................................................................... (1)

(Total 15 marks)

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GCSETrilogyrequiredpracticalactivity:Foodtests1.Testingforcarbohydrates

Inthisexperimentyouwilltestoneormorefoodstuffsforthepresenceofcarbohydrates.

Method


• foodtobetested

• apestleandmortar

• astirringrod

• filterfunnelandfilterpaper

• 2´beaker,250ml

• aconicalflask

• 2´testtube

• Benedict’ssolution

• iodinesolution

• kettleforboilingwater

• athermometer

• safety goggles. 1. Useapestleandmortartogrindupasmallsampleoffood.2. Transferthegroundupfoodintoasmallbeaker.Thenadddistilledwater.3. Stirthemixturesothatsomeofthefooddissolvesinthewater.4. Filterusingafunnelwithfilterpapertoobtainasclearasolutionaspossible.

Thesolutionshouldbecollectedinaconicalflask.

5. Halffillatesttubewithsomeofthissolution.6. Add10dropsofBenedict’ssolutiontothesolutioninthetesttube.7. Puthotwaterfromakettleinabeaker.Thewatershouldnotbeboiling. Putthetesttubeinthebeakerforaboutfiveminutes.8. Noteanycolourchange. Ifareducingsugar(suchasglucose)ispresent,thesolutionwillturngreen,yellow,orbrick-red.Thecolour

dependsonthesugarconcentration.9. Take5mlofthesolutionfromtheconicalflaskandputitintoacleantesttube.10. Addafewdropsofiodinesolutionandnoteanycolourchange. Ifstarchispresent,youshouldseeablackorblue-blackcolourappear.11. Recordyourresultsinatablesuchastheonebelow,

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NameoffoodtestedColourproducedwithBenedict’s

solutionColourproducedwithiodine

solution

Testingforlipids

Inthisexperimentyouwilltestoneormorefoodstuffsforthepresenceoflipids(fats).


• foodtobetested


• astirringrod

• 2´beaker,250ml

• atesttube

• SudanIIIstainsolution.

• safetygoggles.1. Useapestleandmortartogrindupasmallsampleoffood.2. Transferthegroundupfoodintoasmallbeaker.Thenadddistilledwater.3. Stirthemixturesothatsomeofthefooddissolvesinthewater.Donotfilter.4. Halffillatesttubewithsomeofthissolution.5. Add3dropsofSudanIIIstaintothesolutioninthetesttube.Shakegentlytomix.6. If fat is present: a red-stained oil layer will separate out and float on the water surface.

Alternatively

1. Add the sample to a test tube, then add alcohol and shake, 2. Then add water and shake 3. If the solution turns milky, lipids are present

3.Testingforproteins

Inthisexperimentyouwilltestoneormorefoodstuffsforthepresenceofprotein


• foodtobetested


• astirringrod

• afilterfunnelandfilterpaper

• 2´beaker,250ml

• atesttube

• Biuretsolution

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• safetygoggles.

1. Useapestleandmortartogrindupasmallsampleoffood.2. Transferthegroundupfoodintoasmallbeaker.Thenadddistilledwater.3. Stirthemixturesothatsomeofthefooddissolvesinthewater.4. Filterusingafunnelwithfilterpapertoobtainasclearasolutionaspossible.Thesolutionshouldbecollected

inaconicalflask.5. Put2cm3ofthissolutionintoatesttube.6. Add2cm3ofBiuretsolutiontothesolutioninthetesttube.Shakegentlytomix.7. Noteanycolourchange.Proteinswillturnthesolutionpinkorpurple.Questions

Completethetablebelow

Food type Chemical used Test result Reducing sugar Benedicts Turns green/orange brick red when heated with

Benedicts starch

protein

Lipids method 1

Lipids method 2

GCSETrilogyrequiredpracticalactivity:PhotosynthesisRequiredpracticalactivity Apparatusandtechniques

Investigatetheeffectofafactorontherateofphotosynthesisusinganaquaticorganismsuchaspondweed.

AT1,AT3,AT4,AT5

Investigatingtheeffectoflightintensityonphotosynthesisinpondweed

Plantsusecarbondioxideandwatertoproduceglucoseandoxygen.Thisprocessiscalledphotosynthesis.Therateofphotosynthesisisaffectedbymanyfactors,suchas:

• light intensity • light wavelength.

Aquaticplantsproducevisiblebubblesofoxygengasintothesurroundingwaterwhentheyphotosynthesise.Thesebubblescanbecountedasameasureoftherateofphotosynthesis.Pondweedisanexampleofanaquaticplant.

Theeffectoflightintensitycanbeinvestigatedbyvaryingthedistancebetweenpondweedandalightsource.Thecloserthelightsource,thegreaterthelightintensity.

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Riskassessment:

Careshouldbetaken:

• when handling glassware • with the use of lamps that may get hot • with the presence of water and the electrical power supply for the lamp.

Method


• aboilingtube

• freshlycut10cmpieceofpondweed

• alightsource

• aruler

• atesttuberack

• astopwatch

• 0.2%solutionofsodiumhydrogencarbonate

• a glass rod.

Readtheseinstructionscarefullybeforeyoustartwork.

1. Set up a test tube rack containing a boiling tube at a distance of 10 cm away from the light source 2. Fill the boiling tube with the sodium hydrogen carbonate solution. 3. Put the piece of pondweed into the boiling tube with the cut end at the top. Gently push the pondweed

down with the glass rod. 4. Leave the boiling tube for 5 minutes. 5. Start the stop watch and count the number of bubbles produced in one minute.

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6. Record the results in a table such as the one here.

Distancebetweenpondweedandlightsourceincm

Numberofbubblesperminute

1 2 3 Mean

10

20

30

40

7. Repeat the count twice more. Then use the data to calculate the mean number of bubbles per minute. 8. Repeat steps 1‒7 with the test tube rack and boiling tube at distances of 20 cm, 30 cm and 40 cm from

the light source.

Questions

1. What is the independent variable? 2. What is the range of the independent variable in this method? 3. What is the dependent variable? 4. Give at least 3 examples of control variables? 5. What gas is the bubbles that are being counted? 6. By what process is the gas in question 5 produced? 7. When the lamp is closer to the pondweed light intensity is higher, what relationship would you expect to see

between light intensity and the number of bubbles produced? Can you explain this relationship. 8. An efficient bulb which transfers very little energy as waste is used in this experiment explain why. 9. A heat shield such as a piece of clear plastic or a beaker of water is often placed between the lamp and the

pondweed, suggest why.

Q1.In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

Light intensity, carbon dioxide concentration and temperature are three factors that affect the rate of photosynthesis.

How would you investigate the effect of light intensity on the rate of photosynthesis?

The image below shows some of the apparatus you might use.

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You should include details of:

• how you would set up the apparatus and the materials you would use

• the measurements you would make

• how you could make this a fair test.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

...................................................................................................................................... (Total 6 marks)

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Q2.This question is about photosynthesis.

(a) Plants make glucose during photosynthesis. Some of the glucose is changed into insoluble starch.

What happens to this starch?

Tick ( ) one box.

The starch is converted into oxygen.

The starch is stored for use later.

The starch is used to make the leaf green. (1)

(b) A student investigated the effect of temperature on the rate of photosynthesis in pondweed.

The diagram shows the way the experiment was set up.

(i) The student needed to control some variables to make the investigation fair.

State two variables the student needed to control in this investigation.

1.............................................................................................................

2............................................................................................................. (2)

(ii) The bubbles of gas are only produced while photosynthesis is taking place.

What two measurements would the student make to calculate the rate of photosynthesis?

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1.............................................................................................................

2............................................................................................................. (2)

(c) The graph shows the effect of temperature on the rate of photosynthesis in the pondweed.

Temperature in °C

(i) Name the factor that limits the rate of photosynthesis between the points labelled A and B on the graph.

............................................................................................................... (1)

(ii) Suggest which factor, carbon dioxide, oxygen or water, might limit the rate of photosynthesis between the points labelled C and D on the graph.

............................................................................................................... (1)

(Total 7 marks)

Q3.(a) Complete the equation for photosynthesis. Draw a ring around each correct answer.

hydrogen alcohol

Carbon dioxide + nitrogen light energy glucose + oxygen

water methane

(2)

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Some students investigated the effect of light intensity on the rate of photosynthesis in pondweed.

The diagram shows the apparatus the students used.

The closer the lamp is to the pondweed, the more light the pondweed receives.

The students placed the lamp at different distances, d, from the pondweed.

They counted the number of bubbles of gas released from the pondweed in 1 minute for each distance.

(b) A thermometer was placed in the glass beaker.

Why was it important to use a thermometer in this investigation?

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (3)

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(c) The students counted the bubbles four times at each distance and calculated the correct mean value of their results.

The table shows the students’ results.

Distance d in cm

Number of bubbles per minute

1 2 3 4 Mean

10 52 52 54 54 53

20 49 51 48 52 50

30 32 30 27 31 30

40 30 10 9 11

(i) Calculate the mean number of bubbles released per minute when the lamp was 40 cm from the pondweed.

...............................................................................................................

...............................................................................................................

Mean number of bubbles at 40 cm = ............................................ (2)

(ii) On the graph paper below, draw a graph to show the students’ results:

• add a label to the vertical axis • plot the mean values of the number of bubbles • draw a line of best fit.

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Distance d in cm (4)

(iii) One student concluded that the rate of photosynthesis was inversely proportional to the distance of the lamp from the plant.

Does the data support this conclusion?

Explain your answer.

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

(d) Light intensity, temperature and concentration of carbon dioxide are factors that affect the rate of photosynthesis.

Scientists investigated the effects of these three factors on the rate of photosynthesis in tomato plants growing in a greenhouse.

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The graph below shows the scientists’ results.

Light intensity in lux

A farmer in the UK wants to grow tomatoes commercially in a greenhouse.

The farmer read about the scientists’ investigation.

During the growing season for tomatoes in the UK, natural daylight has an intensity higher than 30 000 lux.

The farmer therefore decided to use the following conditions in his greenhouse during the day:

• 20°C

• 0.1% CO2

• no extra lighting.

Suggest why the farmer decided to use these conditions for growing the tomatoes.

You should use information from the scientists’ graph in your answer.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

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........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (4)

(Total 17 marks)

GCSETrilogyrequiredpracticalactivity:ReactionTime Investigatingwhetherpracticereduceshumanreactiontimes

Messagestravelveryquicklyaroundyourbodythroughthenervoussystem.Thisissothatyouareabletorespondtochangesintheenvironment.Thetimeittakesforyoutorespondtosuchachangeiscalledyourreactiontime.

Athletesspendhourspractisingtotrytoreducetheirreactiontime.Thisistohelpthemimprovetheirperformanceintheirparticularsport.Respondingquickertothestarter’spistolinaracecangainyoutheadvantageoverotherrunners.

Youwillconductasimple,measurableexperimentcalledtherulerdroptest.Fromthisyoucandeterminewhetheryourreactiontimecanbereducedwithpractice.


• ametreruler

• achair

• atable

• a partner.

1. Useyourweakerhandforthisexperiment.Ifyouarerighthandedthenyourlefthandisyourweakerhand.2. Sitdownonthechairwithgooduprightpostureandeyeslookingacrosstheroom.3. Placetheforearmofyourweakerarmacrossthetablewithyourhandoverhangingtheedgeofthetable.4. Yourpartnerwillholdarulerverticallywiththebottomend(theendwiththe0cm)inbetweenyourthumband

firstfinger. Practiceholdingtherulerwiththosetwofingers.5. Yourpartnerwilltakeholdoftherulerandaskyoutoremoveyourfingers.6. Yourpartnerwillholdtherulersothezeromarkislevelwiththetopofyourthumb.Theywilltellyouto

preparetocatchtheruler.7. Yourpartnerwillthendroptherulerwithouttellingyou.8. Youmustcatchtherulerasquicklyasyoucanwhenyousensethattherulerisdropping.9. Aftercatchingtheruler,lookatthenumberlevelwiththetopofyourthumb. Recordthisinatablesuchastheonehere.

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DroptestattemptsRulermeasurementsincm Reactiontimesinseconds

Person1 Person2 Person1 Person2

1

2

3

4

5

6

7

8

9

10

10. Haveashortrestandthenrepeatthetest.Recordthenumberontherulerasattempt2.11. Continuetorepeatthetestseveraltimes.12. Swapplaceswithyourpartner.Repeattheexperimenttogettheirresults.13. Useaconversiontabletoconvertyourrulermeasurementsintoreactiontimes.

Q1.Two students investigated reflex action times.


1. Student A sits with his elbow resting on the edge of a table.

2. Student B holds a ruler with the bottom of the ruler level with the thumb of Student A.

3. Student B drops the ruler.

4. Student A catches the ruler and records the distance.

5. Steps 1 to 4 are then repeated.

The same method was also used with Student A dropping the ruler and Student B catching the ruler.

(a) Give two variables the students controlled in their investigation.

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1 ..........................................................................................................................

2 .......................................................................................................................... (2)

(b) Figure 1 shows one of the results for the Student A.

Figure 1

What is the reading shown in Figure 1?

.............................................................................................................................

Reading on ruler = ...................................................... cm (1)

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(c) Table 1 shows the students’ results.

Table 1

Test number

Distance ruler dropped in cm

Student A Student B

1 9 12

2 2 13

3 6 13

4 7 9

5 7 8

Mean 7 X

Circle the anomalous result in Table 1 for Student A. (1)

(d) What is the median result for Student B?

Tick one box.

8

11

12

13

(1)

(e) Calculate the value of X in Table 1.

.............................................................................................................................

Mean distance ruler dropped = .................................... cm

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(1)

(f) Figure 2 shows the scale used to convert distance of the ruler drop to reaction time.

Figure 2

Calculate how much faster the reaction time of Student A was compared to Student B.

Use Figure 2 and Table 1.

.............................................................................................................................

Answer = .......................... s (2)

(g) What improvement could the students make to the method so the results are more valid?

Tick one box.

Use alternate hands when catching the ruler

Carry out more repeats

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Use a longer ruler for catching

Use more than two students to collect results

(1)

(h) Student A carried out a second investigation to see the effect of caffeine on the reflex action.

Table 2 shows his results.

Table 2

Test

number

Distance ruler dropped in cm

Without caffeine With caffeine

1 9 5

2 6 5

3 9 4

4 6 7

5 10 4

Mean 8 5

Give one conclusion about the effect of caffeine on reflex actions.

.............................................................................................................................

............................................................................................................................. (1)

(Total 10 marks)

Q2.Car drivers need quick reactions to avoid accidents.

A student uses a computer program to measure reaction time.

The computer screen shows a traffic light on red. The traffic light then changes to green.

The diagram below shows the change the person sees on the computer screen.

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When the traffic light changes to green the person has to click the computer mouse as quickly as possible.

The computer program works out the time taken to react to the light changing colour.

(a) Special cells detect the change in colour.

(i) What word is used to describe special cells that detect a change in the environment?

Draw a ring around the correct answer.

(1)

(ii) Where in the body are the special cells that detect the change in colour of the traffic lights?

................................................................................................................... (1)

(b) The student used the computer program on one computer to measure the reaction times of people of different ages.

(i) Give one variable the student should control so that a fair comparison can be made between the people of different ages.

...................................................................................................................

................................................................................................................... (1)

(ii) The student did each measurement three times to calculate a mean value.

The table shows the results.

Age in Mean reaction time in

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years milliseconds

15 242

30

45 221

60 258

75 364

90 526

The reaction times for the 30-year-old person were 192, 174 and 180 milliseconds.

Calculate the mean reaction time of the 30-year-old person.

...................................................................................................................

...................................................................................................................

Mean reaction time = ..................................... milliseconds (1)

(iii) Which one of the following is an advantage of repeating each test three times and not doing the test just once?

Tick () one box.

Any anomalies can be identified.

The results will be more precise.

There will be no errors.

(1)

(iv) Some people think that old people should not be allowed to drive a car.

Why is it more dangerous for old people to drive cars?

Use information from the table above to support your answer.

...................................................................................................................

...................................................................................................................

...................................................................................................................

................................................................................................................... (2)

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(Total 7 marks)

Q3.Two students investigated reflex action times.


1. Student A sits with her elbow resting on the edge of a table.

2. Student B holds a ruler with the bottom of the ruler level with the thumb of Student A.

3. Student B drops the ruler.

4. Student A catches the ruler and records the distance, as shown in the diagram below.

5. Steps 1 to 4 were then repeated.

(a) Suggest two ways the students could improve the method to make sure the test would give valid results.

1 .....................................................................................................................

........................................................................................................................

2 .....................................................................................................................

........................................................................................................................

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(2)

(b) The table below shows Student A’s results.

Test Number Distance ruler dropped in mm

1 117

2 120

3 115

4 106

5 123

6 125

7 106

What is the median result?

Tick one box.

106

115

116

117

123

(1)

(c) The mean distance the ruler was dropped is 116 mm.

Calculate the mean reaction time.

Use the equation:

reaction time in s =

Give your answer to 3 significant figures

........................................................................................................................

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........................................................................................................................

........................................................................................................................

Mean reaction time = ............................................ s (3)

(d) The students then measured Student A’s reaction time using a computer program.


1. The computer shows a red box at the start.

2. As soon as the box turns green the student has to press a key on the keyboard as fast as possible.

3. The test is repeated five times and a mean reaction time is displayed.

Student A’s mean reaction time was 110 ms.

Using a computer program to measure reaction times is likely to be more valid than the method using a dropped ruler.

Give two reasons why.

1 .....................................................................................................................

........................................................................................................................

2 .....................................................................................................................

........................................................................................................................ (2)

(e) A woman has a head injury.

Her symptoms include:

• finding it difficult to name familiar objects

• not being able to remember recent events.

Suggest which part of her brain has been damaged.

........................................................................................................................ (1)

(f) A man has a head injury.

He staggers and sways as he walks.

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Suggest which part of his brain has been damaged.

........................................................................................................................ (1)

(Total 10 marks)

GCSETrilogyrequiredpracticalactivity:Fieldinvestigations


Measurethepopulationsizeofacommonspeciesinahabitat.Usesamplingtechniquestoinvestigatetheeffectofafactoronthedistributionofthisspecies.

AT1,AT3,AT4,AT6,AT8

Thisinvestigationhastwoparts:

1.Investigatingthepopulationsizeofaplantspeciesusingrandomsampling

2.Investigatingtheeffectofafactoronplantdistributionusingatransectline.

Method


• a25cmx25cmquadrat

• 2x30mtapemeasure

• aclipboard

• apen

• paper.

1.Investigatingthepopulationsizeofaplantspeciesusingrandomsampling.

Yourteacherwillhavepreparedasurveyareaforyouandwillshowyouhowtoidentifyplantainplants.Youwillneedtoworkinthrees.

1. Collecttwonumbers,onefromeachbag.2.Usethenumbersandthetapemeasurestolocatethefirstpositionforyourquadrat.

3.Laythe25cmx25cmquadratontheground.

4.Replacethenumbersinthebags.

5.Countandrecordthenumberofplantaininsidethequadrat.

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6.Collecttwomorenumbersfromthebagsandusethemtolocatethenextsite.

7.Replacethenumbersinthebagsforotherstudentstouse.

8.Countandrecordthenumberofplantaininsidethequadrat.Repeatsteps1–5untilyouhaverecordedthenumbersofplantainin10quadrats.

10.Yourteacherwillshowyouhowtoestimatethepopulationofplantainusingtheequation:

estimatedpopulationsize= areasampledtotalarea

xnumberofplantaincounted

2.Investigatingtheeffectofafactoronplantdistributionusingatransectline

Yourteacherwillhelpyouidentifyaspeciesofplanttoidentify.

1. Laythe30mtapemeasureinalinefromthebaseofatreetoanopenareaofground.2. Putthe25cmx25cmquadratagainstthetransectline.Onecornerofthequadratshouldtouchthe0mmarkon

thetapemeasure.3. Countthenumberofplantswithinthequadratandrecordtheminatable.

Distancealongthe

transectlineinmNumberofplants Lightintensity

0

5

10

15

20

25

30

4.Movethequadrat5mupthetransectlineandcountthenumberofplantsagain.Recordinthetable.

5.Continuetoplacethequadratat5mintervalsandcountthenumberofplantsineachquadrat.

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6.Gatherdatafromyourclasstoproduceagraphofplantnumbersagainstlightintensity.

Q1.A student was asked to estimate how many clover plants there are in the school field.

The image below shows the equipment used.


1. Throw a quadrat over your shoulder.

2. Count the number of clover plants inside the quadrat.

3. Repeat step 1 and step 2 four more times.

4. Estimate the number of clover plants in the whole field.

(a) What is the tape in the image above used for in this investigation?

.............................................................................................................................

............................................................................................................................. (1)

(b) The teacher told the student that throwing the quadrat over his shoulder was not random.

The method could be improved to make sure the quadrats were placed randomly.

Suggest one change the student could make to ensure the quadrats were placed randomly.

.............................................................................................................................

............................................................................................................................. (1)

(c) How could the student improve the investigation so that a valid estimate can be made?

Tick two boxes.

Weigh the clover plants

Compare their results with another student’s results

Count the leaves of the clover plants

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Place more quadrats

Place the quadrats in a line across the field

(2)

(d) The table below shows the student’s results.

Quadrat number

Number of clover plants

counted

1 11

2 8

3 11

4 9

5 1

Total 40

The area of the school field was 500 m2.

The quadrat used in the table above had an area of 0.25 m2.

Calculate the estimated number of clover plants in the school field.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

Estimated number of clover plants = ................................. (3)

(e) What was the mode for the results in the table above?

Tick one box.

1

8

11

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40

(1)

(f) Suggest which quadrat could have been placed under the shade of a large tree.

Give one reason for your answer.

Quadrat number ....................................

Reason ...............................................................................................................

............................................................................................................................. (1)

(Total 9 marks)

Q2.A grassy field on a farm measured 120 metres by 80 metres.

A student wanted to estimate the number of buttercup plants growing in the field.

The student found an area where buttercup plants were growing and placed a 1 m × 1 m quadrat in one position in that area.

Figure 1 shows the buttercup plants in the quadrat.

The student said, 'This result shows that there are 115 200 buttercup plants in the field.'

(a) (i) How did the student calculate that there were 115 200 buttercup plants in the field?

...............................................................................................................

...............................................................................................................

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...............................................................................................................

............................................................................................................... (2)

(ii) The student’s estimate of the number of buttercup plants in the field is probably not accurate. This is because the buttercup plants are not distributed evenly.

How would you improve the student’s method to give a more accurate estimate?

...............................................................................................................

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

(b) Sunlight is one environmental factor that might affect the distribution of the buttercup plants.

(i) Give three other environmental factors that might affect the distribution of the buttercup plants.

1...............................................................................................................

2...............................................................................................................

3............................................................................................................... (3)

(ii) Explain how the amount of sunlight could affect the distribution of the buttercup plants.

(3)

(c) Figure 2 is a map showing the position of the farm and a river which flows through it.

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Every year, the farmer puts fertiliser containing mineral ions on some of his fields.When there is a lot of rain, some of the fertiliser is washed into the river.

(i) When fertiliser goes into the river, the concentration of oxygen dissolved in the water decreases.

Explain why the concentration of oxygen decreases.

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

............................................................................................................... (5)

(ii) There is a city 4 km downstream from the farm.

Apart from fertiliser, give one other form of pollution that might go into the river as it flows through the city.

............................................................................................................... (1)

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(d) Three sites, A, B and C, are shown in Figure 2.

Scientists took many samples of river water from these sites.

The scientists found larvae of three types of insect in the water: mayfly, stonefly and caddisfly. For each type of insect the scientists found several different species.

The scientists counted the number of different species of the larvae of each of the three types of insect.

Figure 3 shows the scientists’ results.

(i) How many more species of mayfly were there at Site B than at Site A?

........................................ (1)

(ii) Suggest what caused this increase in the number of species of mayfly.

...............................................................................................................

............................................................................................................... (1)

(iii) The scientists stated that the number of species of stonefly was the best indicator of the amount of oxygen dissolved in the water.

Use information from Figure 3 to suggest why. (1)

(Total 19 marks)

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Q3.Some students investigated the distribution of dandelion plants in a grassy field. The grassy field was between two areas of woodland.

Figure 1 shows two students recording how many dandelion plants there are in a 1 metre x 1 metre quadrat.

Figure 1

© Science Photo Library

Figure 2 shows a section across the area studied and Figure 3 shows a bar chart of the students’ results.

Figure 2

Distance in m

Figure 3

Distance in m

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(a) How did the students use the quadrat and the 30-metre tape measure to get the results in Figure 3?

Use information from Figure 1.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (3)

(b) (i) Suggest one reason why the students found no dandelion plants under the trees.

...............................................................................................................

............................................................................................................... (1)

(ii) Suggest one reason why the students found no dandelion plants at 16 metres.

...............................................................................................................

............................................................................................................... (1)

(c) The teacher suggested that it was not possible to make a valid conclusion from these results.

Describe how the students could improve the investigation so that they could make a valid conclusion.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

(Total 7 marks)

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Q4. Some students investigated the distribution of some of the plants growing in and around a shallow stream. They sampled along a transect line.

The diagram shows their results.

(a) (i) Name the one species that grew only in the driest conditions.

........................................................................................................................ (1)

(ii) Only one species grew in the marsh, the swamp and in the aquatic zones.

Which species?

........................................................................................................................ (1)

(iii) Duckweed grows floating in water. What evidence is there for this in the students’ results?

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........................................................................................................................

........................................................................................................................ (1)

(b) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

Describe how you would use a -metre × -metre quadrat frame and a 30-metre tape measure to obtain data similar to the data shown in the diagram.

You should include details of how you would make sure that you would obtain valid results.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (6)

(Total 9 marks)

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GCSETrilogyrequiredpracticalactivity:Makingsalts


Preparationofapure,drysampleofasolublesaltfromaninsolubleoxideorcarbonate,usingaBunsenburnertoheatdiluteacidandawaterbathorelectricheatertoevaporatethesolution.

AT2,AT3,AT4,AT6

PreparationofpuredrycoppersulfatecrystalsYouwillreactanacidandaninsolublebasetoprepareanaqueoussolutionofasalt.Theunreactedbasefromthereactionwillneedtobefiltered.Youwillevaporatethefiltratetoleaveaconcentratedsolutionofthesalt,whichwillcrystalliseasitcoolsandevaporatesfurther.Whendrythecrystalswillhaveahighpurity.Youareprovidedwiththefollowing:• 40cm31.0Mdilutesulfuricacid

• copper(II)oxidepowder

• spatula

• glassrod

• 100cm3beaker

• Bunsenburner

• tripod

• gauze

• heatproofmat

• filterfunnelandpaper

• clampstand

• conicalflask

• 250cm3beaker

• evaporatingbasin

• crystallisingdish1. Measure40cm3sulfuricacidintothe100cm3beaker.2. Setupthetripod,gauzeandheatproofmat.HeattheacidgentlyusingtheBunsenburneruntilitisalmost

boiling.TurnofftheBunsenburner.

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3. Usethespatulatoaddsmallamountsofcopper(II)oxidepowder.Stirwiththeglassrod.

Continuetoaddcopper(II)oxideifitkeepsdisappearingwhenstirred.Whenthe

copper(II)oxidedisappearsthesolutionisclearblue.

4. Stopaddingthecopper(II)oxidewhensomeofitremainsafterstirring.

Allowapparatustocoolcompletely.

5. Setupthefilterfunnelandpaperovertheconicalflask.Usetheclampstandtoholdthefunnel.

Filterthecontentsofthebeakerfromstep3.

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6. Whenfiltrationiscomplete,pourthecontentsoftheconicalflaskintotheevaporatingbasin.

Evaporatethisgentlyusingawaterbath(250cm3beakerwithboilingwater)onthetripodandgauze(seediagram).Stopheatingoncecrystalsstarttoform.

7. Transfertheremainingsolutiontothecrystallisingdish.Leavethisinacoolplaceforatleast24hours.8. Removethecrystalsfromtheconcentratedsolutionwithaspatula.Gentlypatthecrystalsdrybetweentwo

piecesoffilterpaper.

Thesearepuredrycrystalsofcopper(II)sulfate.

Questions

1. Writeawordequationforthereactioninthisexperiment.

2. Completethefollowingequations:

Coppercarbonate+Sulphuricacidà__________+carbondioxide+water

Sodiumhydroxide+Hydrochloricacidà_____________+water

________________+______________àZincNitrate+Water

________________+______________àcopperchloride+carbondioxide+water

3. Instep4,youareadvisedtoensureyoukeepaddingcopperoxideuntilsomeofitstillremainsafterstirring.Thisisknownasaddingthecopperoxidein‘excess’.Explainwhythisisimportant.

4. Instep5,youareaskedtofilterthesolution.Explainwhythisisimportant.

5. Whatdoesthetermfiltratemean?

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Q1. Ammonium nitrate and potassium chloride are both salts. They can be made by neutralisation reactions.

Choose substances from the box to complete the word equations for the formation of these two salts.

ammonia hydrochloric acid nitric acid potassium nitrate water potassium hydroxide

ammonia + ........................................ → ammonium nitrate + water

.................................. + hydrochloric acid → potassium chloride + .......................... (Total 3 marks)

Q2. Salts can be prepared by the reaction of acids with alkalis.

(a) (i) The reactions of acids with alkalis can be represented by the equation below. Choose a substance from the box to complete the equation.

carbon dioxide hydrogen oxygen water

acid + alkali → salt + .......................................................... (1)

(ii) Draw a ring around the word which best describes the reaction.

displacement neutralisation oxidation reduction (1)

(b) Sodium sulphate is an important salt.

The table gives a list of some substances.

Put a tick ( ) next to the names of the acid and the alkali that would react to make sodium sulphate.

Substances ( )

Hydrochloric acid

Nitric acid

Potassium sulphate

Sodium hydroxide

Sodium nitrate

Sulphuric acid

(2) (Total 4 marks)

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Q3.A student investigated the reaction of copper carbonate with dilute sulfuric acid.

The student used the apparatus shown in the figure below.

(a) Complete the state symbols in the equation.

CuCO3 (.....) + H2SO4 (aq) → CuSO4 (aq) + H2O (.....) + CO2 (g) (2)

(b) Why did the balance reading decrease during the reaction?

Tick one box.

The copper carbonate broke down.

A salt was produced in the reaction.

A gas was lost from the flask.

Water was produced in the reaction.

(1)

(c) Describe a safe method for making pure crystals of copper sulfate from copper carbonate and dilute sulfuric acid. Use the information in the figure above to help you.

In your method you should name all of the apparatus you will use.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

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.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (6)

(d) The percentage atom economy for a reaction is calculated using:

The equation for the reaction of copper carbonate and sulfuric acid is:

CuCO3 + H2SO4 → CuSO4 + H2O + CO2

Relative formula masses : CuCO3 = 123.5; H2SO4 = 98.0; CuSO4 = 159.5

Calculate the percentage atom economy for making copper sulfate from copper carbonate.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

Atom economy = ........................................... % (3)

(e) Give one reason why is it important for the percentage atom economy of a reaction to be as high as possible.

.............................................................................................................................

............................................................................................................................. (1)

(Total 13 marks)

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Q4. Bordeaux Mixture controls some fungal infections on plants.

A student wanted to make some Bordeaux Mixture.

(a) The student knew that calcium oxide could be made by heating limestone. Limestone contains calcium carbonate, CaCO3.

(i) Write the word equation for this reaction.

................................................................................................................... (1)

(ii) What type of reaction is this?

................................................................................................................... (1)

(b) The student knew that copper sulphate, CuSO4, could be made by the following general reaction.

acid + base → salt + water

(i) What type of reaction is this?

................................................................................................................... (1)

(ii) The base used is copper oxide. Name and give the chemical formula of the acid used.

Name ................................................................................................................

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Chemical formula ............................................................................................. (2)

(c) The student wrote about how the copper sulphate was made.

“Some of the acid was warmed. Copper oxide was added. The mixture was stirred. More copper oxide was added until no more would react. The mixture was then filtered.”

(i) Why was the acid warmed?

...................................................................................................................

................................................................................................................... (1)

(ii) Copper oxide was added until no more would react. Explain why.

...................................................................................................................

...................................................................................................................

................................................................................................................... (2)

(iii) The filtration apparatus is shown.

Describe and explain what happens as the mixture is filtered.

...................................................................................................................

...................................................................................................................

...................................................................................................................

...................................................................................................................

................................................................................................................... (2)

(Total 10 marks) Q5.Calcium chloride (CaCl2) is a soluble salt.

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Calcium chloride can be made by reacting dilute hydrochloric acid with either solid calcium oxide or solid calcium carbonate.

(a) Name the type of reaction that takes place when dilute hydrochloric acid reacts with calcium oxide.

........................................................................................................................ (1)

(b) Write a balanced symbol equation for the reaction of dilute hydrochloric acid with calcium oxide.

........................................................................................................................ (2)

(c) A student added solid calcium oxide to dilute hydrochloric acid in a beaker.

The student added solid calcium carbonate to dilute hydrochloric acid in another beaker.

Describe one difference between the two reactions that the student would see.

........................................................................................................................

........................................................................................................................ (1)

(d) Describe how crystals of calcium chloride can be made from calcium carbonate and dilute hydrochloric acid.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (4)

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(e) A student dissolved some crystals of a salt in water.

The student added sodium hydroxide solution to the salt solution.

The student added sodium hydroxide solution until it was in excess.

(i) Describe what the student would see if the salt contained calcium ions.

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

(ii) Why does the result you have described in part (e)(i) not prove that the salt contains calcium ions?

...............................................................................................................

............................................................................................................... (1)

(iii) Describe an additional test the student could do that would prove the salt contains calcium ions.

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

(Total 13 marks)

GCSETrilogyrequiredpracticalactivity:Electrolysis


Investigatewhathappenswhenaqueoussolutionsareelectrolysedusinginertelectrodes.Thisshouldbeaninvestigationinvolvingdevelopingahypothesis.

AT3,AT7,AT8

Investigatingtheelementsformedateachelectrodewhendifferentsaltsolutionsareelectrolysed

Youwillusealowvoltagepowersupplyandcarbonrodelectrodestopassacurrentthroughfourdifferentsaltsolutions.Youwillidentifytheelementformedatthepositiveandnegativeelectrodeineachcase.

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Method


• copper(II)chloridesolution

• copper(II)sulfatesolution

• sodiumchloridesolution

• sodiumsulfatesolution

• 100cm3beaker

• petridishlid

• twocarbonrodelectrodes

• twocrocodile/4mmplugleads

• lowvoltagepowersupply

• bluelitmuspaper

• tweezers.1. Pourcopper(II)chloridesolutionintothebeakertoabout50cm3.2. Addthelidandinsertcarbonrodsthroughtheholes.Therodsmustnottoucheachother.

Attachcrocodileleadstotherods.Connecttherodstothedc(redandblack)terminalsofalowvoltagepowersupply.

3. Select4Vonthepowersupplyandswitchon.4. Lookatbothelectrodes.Istherebubblingatneither,oneorbothelectrodes?5. Usetweezerstoholdapieceofbluelitmuspaperinthesolutionnexttothepositiveelectrode(theone

connectedtotheredterminal).Youwillneedtoliftthelidtemporarilytodothis.

Writeyourobservationsinthefirstblankrowofthetablebelow.Whatisthiselement?

SolutionPositiveelectrode(anode) Negativeelectrode(cathode)

Observations Elementformed Observations Elementformed

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Copper(II)chloride

Copper(II)sulfate

Sodium

chloride

Sodium

sulfate

6. Afternomorethanfiveminutes,switchoffthepowersupply.

Examinethenegativeelectrode(theoneconnectedtotheblackterminal).Isthereevidenceofametalcoatingonit?Whatcoulditbe?

Recordyourresultsinthetable.

7. Cleantheequipmentcarefully.

Repeatsteps1‒6usingsolutionsof:

• copper (II) sulfate

• sodium chloride

• sodium sulfate.

AdditionalinformationGasproducedatthepositiveelectrodewhichdoesnotbleachbluelitmuspaper,isoxygen.Theamountsproducedareusuallytoosmalltoidentifybytesting.Ifagasisproducedatthenegativeelectrode,itishydrogen.Theamountsproducedareusuallytoosmalltoidentifybytesting.

Questions

1. Whatisthenameforthepositiveelectrode?2. Whatisthenameforthenegativeelectrode?3. Whenlitmuspaperisbleached,whatgasispresent?4. Howdoyoutestagastofindoutifitisoxygen?5. Howdoyoutestagastofindoutifitishydrogen?6. Howdoyoutestagastofindoutifitiscarbondioxide?

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Q1.This question is about zinc.

Figure 1 shows the electrolysis of molten zinc chloride.

(a) Zinc chloride is an ionic substance. Complete the sentence.

When zinc chloride is molten, it will conduct .................................................. . (1)

(b) Zinc ions move towards the negative electrode where they gain electrons to produce zinc.

(i) Name the product formed at the positive electrode.

....................................................................... (1)

(ii) Explain why zinc ions move towards the negative electrode.

...................................................................................................................

...................................................................................................................

...................................................................................................................

................................................................................................................... (2)

(iii) What type of reaction occurs when the zinc ions gain electrons?

Tick () one box.

Neutralisation

Oxidation

Reduction

(1)

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(c) Zinc is mixed with copper to make an alloy.

(i) Figure 2 shows the particles in the alloy and in pure zinc.

Use Figure 2 to explain why the alloy is harder than pure zinc.

...................................................................................................................

...................................................................................................................

...................................................................................................................

................................................................................................................... (2)

(ii) Alloys can be bent. Some alloys return to their original shape when heated.

What name is used for these alloys?

................................................................................................................... (1)

(Total 8 marks)

Q2. The diagram shows apparatus used by a student to investigate electrolysis.

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The student was given a solution by the teacher. The solution contained a mixture of ionic compounds.

(a) Name the particles which carry the electric current through:

(i) the metal wires ..................................................................................... (1)

(ii) the solution. .......................................................................................... (1)

(b) The table shows the ions in the solution.

Positive ions in the solution Negative ions in the solution

Zinc ion (Zn2+) Chloride ion (Cl–)

Iron(III) ion (Fe3+) Hydroxide ion (OH–)

Hydrogen ion (H+) Nitrate ion (NO3–)

Copper(II) ion (Cu2+) Sulfate ion (SO42–)

The reactivity series on the Data Sheet may help you to answer this question.

(i) Which element is most likely to be formed at the negative electrode?

............................................................................................................... (1)

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(ii) Explain, as fully as you can, why you have chosen this element.

...............................................................................................................

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

(c) The electrolysis of sodium chloride solution is an industrial process.

(i) The reaction at one of the electrodes can be represented by the equation shown below.

2Cl– → Cl2 + 2e–

The chloride ions (Cl–) are oxidised.

Explain why.

...............................................................................................................

............................................................................................................... (1)

(ii) The reaction at the other electrode can be represented by an equation.

Complete and balance the equation for the reaction at the other electrode.

H+ → H2

(1)

(Total 7 marks)

Q3. A student investigated the electrolysis of sodium chloride solution.

Five sodium chloride solutions were made. Each solution had a different concentration.

To make each solution the student:

• weighed the amount of sodium chloride needed

• dissolved it in water

• added more water until the total volume was one cubic decimetre (1 dm3).

The solutions were placed one at a time in the apparatus shown below.

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The student measured the volume of hydrogen gas produced in ten minutes.

The results are shown on the graph below.

(a) Sodium chloride does not conduct electricity when it is solid.

Explain, in terms of ions, why sodium chloride solution conducts electricity.

........................................................................................................................

........................................................................................................................ (1)

(b) Chlorine is produced at the positive electrode.

Why are chloride ions attracted to the positive electrode?

........................................................................................................................ (1)

(c) The solution left at the end of each experiment contains sodium hydroxide.

Draw a ring around one number which could be the pH of this solution.

2 5 7 13

(1)

(d) The results for the experiment above are shown on the graph.

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(i) Draw a line of best fit on the graph. (1)

(ii) The result for one concentration is anomalous. Which result is anomalous?

The result at concentration ........................ grams per dm3

(1)

(iii) Suggest two possible causes of this anomalous result.

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1 ............................................................................................................

...............................................................................................................

2 ............................................................................................................

............................................................................................................... (2)

(iv) Suggest how the student could check the reliability of the results.

...............................................................................................................

............................................................................................................... (1)

(iv) How did an increase in the concentration of the sodium chloride solution affect the volume of hydrogen gas produced in ten minutes?

...............................................................................................................

............................................................................................................... (1)

(Total 9 marks)

Q4. The electrolysis of sodium chloride solution produces useful substances.

(a) Explain the meaning of electrolysis.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(b) The diagram shows an apparatus used for the electrolysis of sodium chloride solution.

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Reproduced with the permission of Nelson Thornes Ltd from PATRICK FULLICK et al, ISBN 0-7487-9644- 4. First published in 2006

The electrolysis produces two gases, chlorine and Gas A.

Name Gas A ............................................................................................................... (1)

(c) The electrodes used in this process can be made of graphite. Explain why graphite conducts electricity.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(Total 5 marks)

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GCSETrilogyrequiredpracticalactivity:Temperaturechanges


Investigatethevariablesthataffecttemperaturechangesinreactingsolutionssuchas,egacidplusmetals,acidpluscarbonates,neutralisations,displacementofmetals.

AT1,AT3,AT5,AT6

Investigationofthetemperaturechangeswhichtakeplacewhenanacidisneutralisedbyanalkali

Youwillmonitorthetemperatureriseassmallvolumesofsodiumhydroxidesolutionareaddedtodilutehydrochloricacid.Theacidwillbecontainedinaninsulatedcup.

Plotagraphofyourresults.Determinehowmuchsodiumhydroxidewasneededtofullyreactwiththeacid.


• 2Mdilutehydrochloricacid

• 2Msodiumhydroxidesolution

• expandedpolystyrenecupandlid

• 250cm3beaker



• thermometer.1. Usethe50cm3measuringcylindertoput30cm3dilutehydrochloricacidintothe

polystyrenecup.

2. Standthecupinsidethebeaker.Thiswillmakeitmorestable.3. Usethethermometertomeasurethetemperatureoftheacid.Recorditinthefirstblankcolumnofthetable

suchastheonebelow.4. Put5cm3sodiumhydroxidesolutionintothe10cm3measuringcylinder.5. Pourthesodiumhydroxideintothecup.Fitthelidandgentlystirthesolutionwiththethermometerthrough

thehole.

Whenthereadingonthethermometerstopschanging,writethetemperatureinthenextspaceinthetable.

6. Repeatsteps4and5toaddfurther5cm3amountsofsodiumhydroxidetothecup.Atotalof40cm3needstobeadded.

Thelastfewadditionsshouldproduceatemperaturefallratherthanarise.

7. Repeatsteps1–6andrecordtheresultsinthesecondblankcolumnofthetable.8. Calculatethemeanmaximumtemperaturereachedforeachofthesodiumhydroxidevolumes.Recordthese

meansinthethirdblankcolumn.

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Totalvolumeofsodiumhydroxide

addedincm3

MaximumtemperatureinoC

Firsttrial Secondtrial Mean

0

5

10

15

20

25

30

35

40

9. Plot a graph with:

• ‘Mean maximum temperature in oC’ on the y-axis

• ‘Total volume of sodium hydroxide added in cm3’ on the x-axis.

Drawtwostraightlinesofbestfit:

• one through the points which are increasing

• one through the points which are decreasing. Ensure the two lines are extended so they cross each other.

10. Usethegraphtoestimatehowmuchsodiumhydroxidesolutionwasneededtoneutralise25cm3dilutehydrochloricacid.

Questions

1. Whenthesodiumhydroxideandthehydrochloricacidareaddedtogether,thetemperaturerises.Whattypeofreactionisthis,endothermicorexothermic?Explainyouranswer

2. Explainwhytheexperimentiscarriedoutinaninsulatedcup.3. Explainwhyyoudrawtwolinesonthegraphasdescribedinstep8.

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Q1.Read the information about energy changes and then answer the questions.

A student did an experiment to find the energy change when hydrochloric acid reacts with sodium hydroxide.

The equation which represents the reaction is:

HCl + NaOH → NaCl + H2O

The student used the apparatus shown in the diagram.

The student placed 50 cm3 of hydrochloric acid in a glass beaker and measured the initial temperature.

The student then quickly added 50 cm3 of sodium hydroxide solution and stirred the mixture with the thermometer. The highest temperature was recorded.

The student repeated the experiment, and calculated the temperature change each time.

Experime

nt 1 Experime

nt 2 Experime

nt 3 Experime

nt 4

Initial temperature in °C

19.0 22.0 19.2 19.0

Highest temperature in °C

26.2 29.0 26.0 23.5

Temperature change in °C

7.2 7.0 6.8 4.5

(a) The biggest error in this experiment is heat loss.

Suggest how the apparatus could be modified to reduce heat loss.

........................................................................................................................

........................................................................................................................ (1)

(b) Suggest why it is important to mix the chemicals thoroughly.

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........................................................................................................................ (1)

(c) Which one of these experiments was probably done on a different day to the others?

Give a reason for your answer.

........................................................................................................................ (1)

(d) Suggest why experiment 4 should not be used to calculate the average temperature change.

........................................................................................................................

........................................................................................................................ (1)

(e) Calculate the average temperature change from the first three experiments.

........................................................................................................................

Answer = .................................................. °C (1)

(f) Use the following equation to calculate the energy change for this reaction.

Energy change in joules = 100 × 4.2 × average temperature change

........................................................................................................................

Answer = .................................................. J (1)

(g) Which one of these energy level diagrams represents the energy change for this reaction?


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........................................................................................................................

........................................................................................................................ (1)

(Total 7 marks)

Q2.A student investigates the energy released when hydrochloric acid completely neutralises sodium hydroxide solution. The student uses the apparatus shown in Figure 1.

The student: • measures 25 cm3 sodium hydroxide solution into a polystyrene cup • fills a burette with hydrochloric acid • measures the temperature of the sodium hydroxide solution • adds 5 cm3 hydrochloric acid to the sodium hydroxide solution in the polystyrene cup • stirs the mixture and measures the highest temperature of the mixture • continues to add 5 cm3 portions of hydrochloric acid, stirring and measuring the highest

temperature of the mixture after each addition.

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(a) The student has plotted a graph of the results.

The graph line has been incorrectly drawn by including an anomalous result.

The graph is shown in Figure 2.

(i) Suggest a cause for the anomalous result when 20 cm3 of hydrochloric acid is added.

...............................................................................................................

............................................................................................................... (1)

(ii) Suggest the true value of the temperature of the anomalous point.

Temperature = .............................. °C (1)

(iii) What was the total volume of the mixture when the maximum temperature was reached?

...............................................................................................................

Total volume of the mixture = .............................. cm3

(1)

(iv) Calculate the overall temperature increase in this experiment.

...............................................................................................................

Overall temperature increase = .............................. °C (1)

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(v) Use your answers to (iii) and (iv) and the equation to calculate the energy released in the reaction. Give the unit.

Assume the volume in cm3 is equivalent to the mass of solution in grams.

Equation: Q = mcΔT

where: Q = energy released m = mass of solution (g) c = 4.2 (J per g per °C) ΔT = change in temperature (°C)

...............................................................................................................

...............................................................................................................

Energy released = .............................. Unit = .................... (2)

(b) The student did the experiment again, starting with 50 cm3 of sodium hydroxide solution instead of 25 cm3.

Explain why this would make no difference to the overall temperature increase.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

(Total 8 marks)

GCSETrilogyrequiredpracticalactivity:Ratesofreaction


Investigatehowchangesinconcentrationaffecttheratesofreactionsbyamethodinvolvingmeasuringthevolumeofagasproducedandamethodinvolvingachangeincolourorturbidity.

Thisshouldbeaninvestigationinvolvingdevelopingahypothesis.

AT1,AT3,AT5,AT6

Investigationintohowtheconcentrationofasolutionaffectstherateofachemicalreaction

Therearetwopartstothispracticalwhichinvestigatehowtherateofreactioncanbemeasured.

Activity 1: Observing colour change

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Youwillreactsodiumthiosulfatewithhydrochloricacid.Youwillthenfindouthowtherateofreactionchangesasthethiosulfatesolutionbecomesmoredilute.

Activity 2: Measuring the volume of gas produced

Youwillreactmagnesiumribbonandhydrochloricacid.Youwillthenfindouthowtherateofreactionisaffectedbytheconcentrationoftheacid.

Activity 1: Observing colour change Youareprovidedwiththefollowing:

• 40g/dm3sodiumthiosulfatesolution

• 2.0Mdilutehydrochloricacid



• 100cm3conicalflask

• printedblackpapercross

• stopclock.

1. Useameasuringcylindertoput10cm3sodiumthiosulfatesolutionintotheconicalflask.

Usethemeasuringcylindertothenadd40cm3water.Thisdilutesthesodiumthiosulfatesolutiontoaconcentrationof8g/dm3.

Puttheconicalflaskontheblackcross.2. Put10cm3ofdilutehydrochloricacidintothe10cm3measuringcylinder.3. Putthisacidintotheflask.Atthesametimeswirltheflaskgentlyandstartthestopclock.4. Lookdownthroughthetopoftheflask.Stoptheclockwhenyoucannolongerseethecross.

Takecaretoavoidbreathinginanysulfurdioxidefumes.

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5. Writethetimeittakesforthecrosstodisappearinthefirstblankcolumnofthetablesuchastheonebelow.Recordthetimeinseconds.

Youwillneedtomultiplyanyminutesby60andthenaddtheextraseconds.

Concentrationofsodiumthiosulfateing/dm3

Timetakenforcrosstodisappearinseconds

Firsttrial Secondtrial Thirdtrial Mean

8

16

24

32

40

6. Repeatsteps1‒5fourtimes,butinstep1use:

• 20cm3sodiumthiosulfate+30cm3water(concentration16g/dm3)



• 50cm3sodiumthiosulfate+nowater(concentration40g/dm3)

7. Thenrepeatthewholeinvestigation(steps1–5)twicemore.

Recordtheresultsinthesecondandthirdblankcolumnsofthetable.

8. Calculatethemeantimeforeachofthesodiumthiosulfateconcentrations.Leaveoutanomalousvaluesfromyourcalculations.

Recordthemeansinthefourthblankcolumn.


• ‘mean time taken for cross to disappear in seconds’ on the y-axis

• ‘Sodium thiosulfate concentration in g/dm3’ on the x-axis

Drawasmoothcurvedlineofbestfit.

QuestionsRatesActivity1

1. Whatistheindependentvariableinthisreaction?2. Whatistherangeoftheindependentvariableinthisreaction?3. Whatisthedependentvariable?4. Whatarethecontrolvariablesforthisreaction?5. Explainwhythecrossdisappearsfromview

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6. Whatpatternwouldyouexpecttoseeinthisexperiment?Explainyouranswer.7. Whatdoyouthinkwillbethebiggestsourceoferrorinthisexperiment?Explainyouranswer.

Activity2:Measuringthevolumeofgasproduced


• safetygoggles

• conicalflask(100cm3)

• single-holedrubberbunganddeliverytubetofitconicalflask

• troughorplasticwashing-upbowl

• twomeasuringcylinders(100cm3)

• clampstand,bossandclamp

• stopclock

• graphpaper

• magnesiumribboncutinto3cmlengths

• dilutehydrochloricacid,(2.0M,and1.0M).

1. Measure50cm3of2.0Mhydrochloricacidusingoneofthemeasuringcylinders.Pourtheacidintothe100cm3conicalflask.

2. Setuptheapparatusasshowninthediagram.

Halffillthetroughorbowlwithwater.

3. Fill the other measuring cylinder with water. Make sure it stays filled with water when you turn it upside down.

4. When you are ready, add a 3 cm strip of magnesium ribbon to the flask, put the bung back into the flask as quickly as you can, and start the stopclock.

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5. Record the volume of hydrogen gas given off at suitable intervals (eg 10 seconds) in a table such as the one below.

Continue timing until no more gas appears to be given off.

Time in seconds Volume of gas produced for 2.0 M hydrochloric acid in cm3

10

20

30

40

50

60

70

80

90

100

6. Repeat steps 1-5 using 1.0 M hydrochloric acid. 7. Plot a graph with:

• ‘Volume of gas produced in cm3 (for 2.0 M hydrochloric acid)’ on the y-axis

• ‘Time in seconds’ on the x-axis Draw a smooth curved line of best fit.

8. Plot a curve for 1.0 M hydrochloric acid on the same graph. 9. Use this graph to compare the rates of reaction of 1.0 M and 2.0 M hydrochloric acid with magnesium

QuestionsRatesactivity2

1. Whatwastheindependentvariable?2. Whatwasthedependentvariable?3. Whatarethemaincontrolvariables?4. Describeandexplainthepatternyouwouldexpecttosee.5. Insteadofanupsidedownmeasuringcylinderinatroughofwater,whatalternative

pieceofequipmentcouldbeusedtomeasurethevolumeofgasproduced.

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Q1.Lithium carbonate reacts with dilute hydrochloric acid.

A group of students investigated the volume of gas produced.


1. Place a known mass of lithium carbonate in a conical flask. 2. Measure 10 cm3 of dilute hydrochloric acid using a measuring cylinder. 3. Pour the acid into the conical flask. 4. Place a bung in the flask and collect the gas as shown in Figure 1.

Figure 1

(a) Figure 2 shows the measuring cylinder.

Figure 2

What volume of gas has been collected?

Volume = .......................................... cm3

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(1)

(b) The table below shows the students’ results.

Mass of lithium carbonate in g Volume of gas in cm3

0.0 0

0.1 22

0.2 44

0.3 50

0.4 88

0.5 96

0.6 96

0.7 96

On Figure 3: • Plot these results on the grid. • Complete the graph by drawing two straight lines of best fit.

Figure 3

(4)

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(c) What are two possible reasons for the anomalous result?

Tick two boxes.

Too much lithium carbonate was added.

The bung was not pushed in firmly enough.

There was too much water in the trough.

The measuring cylinder was not completely over the delivery

The conical flask was too small.

(2)

(d) Describe the pattern the graph shows up to 0.4 g of lithium carbonate added.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(e) Lithium carbonate decomposes when heated.

The equation shows the decomposition of lithium carbonate.

Li2CO3 (s) → Li2O (s) + CO2 (g)

Figure 4 shows the apparatus a student used to decompose lithium carbonate.

Figure 4

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Why does the limewater bubble?

.............................................................................................................................

............................................................................................................................. (1)

(f) The student repeated the experiment with potassium carbonate. The limewater did not bubble.

Suggest why there were no bubbles in the limewater.

.............................................................................................................................

............................................................................................................................. (1)

(Total 11 marks)

Q2.A student investigated the rate of reaction between marble chips and hydrochloric acid.

Figure 1 shows the apparatus the student used.

Figure 1

(a) What is A?

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Tick one box.

cotton wool

Limestone

poly(ethene)

rubber bung

(1)

(b) Table 1 shows the student’s results for one investigation.

Table 1

Time in s

Mass lost in g

0 0.0

20 1.6

40 2.6

60 2.9

80 3.7

100 4.0

120 4.0

On Figure 2: • Plot these results on the grid. • Draw a line of best fit.

Figure 2

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(3)

(c) Use Figure 2 to complete Table 2.

Table 2

Mass lost after 0.5 minutes ............ g

Time taken to complete the reaction ............ s

(2)

(d) The equation for the reaction is:

2HCl(aq) + CaCO3(s) → CaCl2(aq) + H2O(l) + CO2(g)

Explain why there is a loss in mass in this investigation.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

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(e) Another student investigated the rate of a different reaction.

Table 3 shows the results from the different reaction.

Table 3

Mass lost when the reaction was complete 9.85 g

Time taken to complete the reaction 2 minutes 30

seconds

Calculate the mean rate of the reaction using Table 3 and the equation:

mean rate of reaction =

Give your answer to two decimal places.

.............................................................................................................................

.............................................................................................................................

Mean rate of reaction = .......................................... g / s (2)

(f) The student measured the change in mass of the reactants.

Describe another method, other than measuring the change in mass of the reactions, that the student could have used to find the rate of the reaction between marble chips and hydrochloric acid.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

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(g) Another student planned to investigate the effect of temperature on the rate of reaction. The student predicted that the rate of reaction would increase as the temperature was increased.

Give two reasons why the student’s prediction is correct.

Tick two boxes.

The particles are more concentrated.

The particles have a greater mass.

The particles have a larger surface area.

The particles have more energy.

The particles move faster.

(2)

(Total 14 marks)

Q3.A student investigated the effect of temperature on the rate of a reaction. The picture below shows an experiment.

The student:

• put sodium thiosulfate solution into a conical flask • heated the sodium thiosulfate solution to the required temperature • put the flask on a cross drawn on a piece of paper • added dilute hydrochloric acid and started a stopclock • stopped the stopclock when the cross could no longer be seen • repeated the experiment at different temperatures.

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The equation for the reaction is:

(a) Explain why the solution goes cloudy.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(b) Give two variables the student must control to make the investigation a fair test.

1 ..........................................................................................................................

2 .......................................................................................................................... (2)

(c) State the effect that increasing the temperature of the sodium thiosulfate solution has on the rate of the reaction. Explain this effect in terms of particles and collisions.

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(d) Suggest how the student should change the method to investigate the rate of reaction at 5°C.

.............................................................................................................................

............................................................................................................................. (1)

(Total 9 marks)

Q4.Marble chips are mainly calcium carbonate (CaCO3).

A student investigated the rate of reaction between marble chips and hydrochloric acid (HCl).

Figure 1 shows the apparatus the student used.

Figure 1

(a) Complete and balance the equation for the reaction between marble chips and hydrochloric acid.

.................. + .................. → CaCl2 + .................. + .................. (2)

(b) The table below shows the student’s results.

Time in s

Volume of gas

in dm3

0 0.000

30 0.030

60 0.046

90 0.052

120 0.065

150 0.070

180 0.076

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210 0.079

240 0.080

270 0.080

On Figure 2:

• Plot these results on the grid.

• Draw a line of best fit.

Figure 2

(4)

(c) Sketch a line on the grid in Figure 2 to show the results you would expect if the experiment was repeated using 20 g of smaller marble chips.

Label this line A. (2)

(d) Explain, in terms of particles, how and why the rate of reaction changes during the reaction of calcium carbonate with hydrochloric acid.

.............................................................................................................................

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............................................................................................................................. (4)

(e) Another student investigated the rate of reaction by measuring the change in mass.

Figure 3 shows the graph plotted from this student’s results.

Figure 3

Use Figure 3 to calculate the mean rate of the reaction up to the time the reaction is complete.

Give your answer to three significant figures.

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.............................................................................................................................

.............................................................................................................................

Mean rate of reaction = ........................................... g / s (4)

(f) Use Figure 3 to determine the rate of reaction at 150 seconds.

Show your working on Figure 3.

Give your answer in standard form.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

Rate of reaction at 150 s = ........................................... g / s (4)

(Total 20 marks)

GCSETrilogyrequiredpracticalactivity:Chromatography


Investigatehowpaperchromatographycanbeusedtoseparateandtellthedifferencebetweencolouredsubstances.StudentsshouldcalculateRfvalues.

AT1,AT4

Investigationintotheuseofpaperchromatographytoseparateandidentifyamixtureoffoodcolourings

Youwillusepaperchromatographytoseparatethedifferentcolourspresentinanunknownmixtureoffoodcolourings.YouwillthenmeasurethedistancetravelledbyeachcolourandthesolventstocalculateRfvalues.


• 250cm3beaker

• glassrod

• arectangleofchromatographypaper

• fourknownfoodcolouringslabelledA-D

• anunknownmixtureoffoodcolouringslabelledU

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• glasscapillarytubes.1. Usearulertodrawahorizontalpencilline2cmfromashortedgeofthechromatographypaper.

Markfivepencilspotsatequalintervalsacrosstheline.Keepatleast1cmawayfromeachend.

2. Useaglasscapillarytubetoputasmallspotofeachoftheknowncolouringsonfourofthepencilspots.Thenusetheglasscapillarytubetoputasmallspotoftheunknownmixtureonthe5thpencilspot.

Trytomakesureeachspotisnomorethan5mmindiameter.Labeleachspotinpencil.

3. Pourwaterintothebeakertoadepthofnomorethan1cm.4. Tapetheedgeofthechromatographypapertotheglassrod.Thepaperneedstobetapedattheendfurthest

fromthespots.Resttherodonthetopedgeofthebeaker.Thebottomedgeofthepapershoulddipintothewater.

Ensurethatthe:

• pencillineisabovethewatersurface

• sidesofthepaperdonottouchthebeakerwall.

5. Waitforthewatersolventtotravelatleastthreequartersofthewayupthepaper.Donotdisturbthebeakerduringthistime.

6. Carefullyremovethepaper.Drawanotherpencillineonthedrypartofthepaperasclosetothewetedgeaspossible.

7. Hangthepaperuptodrythoroughly.Measurethedistanceinmmbetweenthetwopencillines.Thisisthedistancetravelledbythewatersolvent.

8. Measureandrecordthesamedistanceforeachfoodcolouringinthetablebelow.

FoodcolouringDistancetravelledinmm

RfvalueSolvent Spot

A

B

C

D

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9. Foreachofthefourknowncolours,measurethedistanceinmmfromthebottomlinetothecentreofeachspot.Writeeachmeasurementinthetable.

10. UsethefollowingequationtocalculatetheRfvalueforeachoftheknowncolours.

Rf=distancemovedbysubstancedistancemovedbysolvent

11. Writethecalculatedvaluesinthetable.

12. MatchthespotsinmixtureUwiththosefromA–D.Usethecolouranddistancetravelledtohelpyou.

Questions

Youhavebeenadvisedtodrawthestartlineandlabelthespotsinpencil.Explainwhy

Q1.Colours are used to coat some chocolate sweets.

Some of these colours are given E-numbers.

Use the correct word from the box to complete the sentence.

additive element fuel

An E-number is used to identify a permitted food ........................................................ (1)

(b) Chromatography was used to compare three of the colours used to coat the chocolate sweets.

What do these results tell you about these three colours?

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........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (3)

(Total 4 marks)

Q2.Chromatography can be used to separate components of a mixture.

(a) A student used paper chromatography to analyse a black food colouring.

The student placed spots of known food colours, A, B, C, D and E, and the black food colouring on a sheet of chromatography paper.

The student set up the apparatus as shown in Diagram 1.

Diagram 1

The student made two errors in setting up the apparatus. Identify the two errors and describe the problem each error would cause.

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......................................................................................................................... (4)

(b) A different student set up the apparatus without making any errors.

The chromatogram in Diagram 2 shows the student’s results.

Diagram 2

(i) What do the results tell you about the composition of the black food colouring?

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

(ii) Use Diagram 2 to complete Table 1.

Table 1

Distance in mm

Distance from start line to solvent front .............................

Distance moved by food colour C .............................

(2)

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(iii) Use your answers in part (b) (ii) to calculate the Rf value for food colour C.

...............................................................................................................

...............................................................................................................

Rf value = ........................................ (1)

(c) Table 2 gives the results of chromatography experiments that were carried out on some known food colours, using the same solvent as the students.

Table 2

Name of food colour

Distance from start line to solvent

front in mm Distance moved by food colour in mm Rf value

Ponceau 4R 62 59 0.95

Carmoisine 74 45 0.61

Fast red 67 27 0.40

Erythrosine 58 17 0.29

Which of the food colours in Table 2 could be food colour C from the chromatogram?

Give the reason for your answer.

.........................................................................................................................

.........................................................................................................................

......................................................................................................................... (2)

(d) Two types of chromatography are gas chromatography and paper chromatography.

Give one advantage of gas chromatography compared with paper chromatography.

.........................................................................................................................

......................................................................................................................... (1)

(Total 12 marks)

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Q3.This is part of an article about food additives.

THE PERIL OF FOOD ADDITIVES

Some orange drinks contain the additives E102 (Tartrazine), E104 (Quinoline Yellow) and E110 (Sunset Yellow).These three coloured additives are thought to cause hyperactivity in children.

(a) State two reasons that a manufacturer might give to justify the use of these additives.

1 ....................................................................................................................

.......................................................................................................................

2 .....................................................................................................................

....................................................................................................................... (2)

(b) Some scientists asked 4000 twelve-year-old children to help them investigate if there is a link between these three coloured additives and hyperactivity.

How would the scientists use these 4000 children to investigate if there is a link between these three coloured additives and hyperactivity in children?

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........................................................................................................................ (4)

(c) A manufacturer used an independent scientist to show that their orange drink did not contain these three coloured additives.

(i) Suggest why the manufacturer would use a scientist who was independent instead of using their own scientist.

...............................................................................................................

..............................................................................................................(1)

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(ii) The scientist had samples of E102, E104 and E110 and the orange drink. The scientist used paper chromatography for the test.

Describe how the scientist could use the results to show if the orange drink contained any of these three coloured additives.

You may include a diagram of the paper chromatography results.

...............................................................................................................

...............................................................................................................

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............................................................................................................... (2)

(Total 9 marks)

GCSETrilogyrequiredpracticalactivity:WaterpurificationRequiredpracticalactivity ApparatusandTechniques

Analysisandpurificationofwatersamplesfromdifferentsources,includingpH,dissolvedsolidsanddistillation.

AT2,AT3,AT4

AnalysisandDistillationofwaterfromdifferentsources

InthisinvestigationyouwilltestthreewatersamplesfromdifferentsourcesforpHandthepresenceofdissolvedsolids.Afterdistillationoftheseawater,youwilltestthewateragaintocheckthatdissolvedsolidshavebeenremoved,makingthewaterfittodrink.


• watersamples• universalindicator• testtubesandrack• Bunsenburner• 10cm3measuringcylinder

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• tripod• gauze• heatproofmat• 250cm3beaker• watchglass• tongs• clampstand• 250cm3conicalflask• deliverytubewithbung• iceYoushouldreadtheseinstructionscarefullybeforeyoustartwork.

1. Pouraround1cmdepthoftheseawaterintoatesttubeintherack.Addafewdropsofuniversalindicatorsolution.UsingapHcolourchart,matchthecolourandrecordthepHofthewaterintheresultstable.Repeatthistestforspringwaterandrainwaterandrecordtheresults.2. Weighadrywatchglass.Recorditsmassinthetable.Pour4cm3seawater(lessifyourwatchglassissmall)intoitandplaceitaboveabeakeractingasawaterbathasshowninthediagram.3. Allowallthewatertoevaporatefromthewatchglass.Donotletthewaterbathboildry.

4. Youshouldseedissolvedsolidsontheglass.Removethewatchglasswithtongsandallowtocool.Drythebottomofthewatchglasswithaclothandreweighit.Recordthenewmassinthetable.Subtractthemassofthewatchglassaloneandrecordthemassofthedissolvedsolids.Washthewatchglassanddryit.

5. Repeatsteps2–4fortheotherwatersamples.Youdonotneedtoweightheemptywatchglassagainaslongasyouusethesameoneeachtime.

6. Placetheremainingseawater(around40cm3)intheconicalflaskandsetuptheapparatusfor

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distillationasshowninthediagram.7. Makesuretheconicalflaskisheldonthetripodandgauzeusingtheclampstand.Placeamixtureoficeand

waterinthebeakersurroundingthetesttube.8. HeattheseawaterwiththeBunsenburneruntilitstartstoboil.Thenreducetheheatsothatthewaterboils

gently.Distilledwaterwillcollectinthecooledtesttube.Collectabout5cmdepthofwaterinthisway,thenstopheating.

9. Repeatthetestsinsteps1to4againusingthedistilledseawater,againrecordingyourresultsinthetable.

Questions

1. Step7asksyoutoplacethemixtureinabeakeroficeandwater.Explainwhythisstepisnecessary.2. Insteps1–4crystalsshouldformonthewatchglassbeforethewaterhasbeendistilled.Explainwhythisis.3. Afterthewaterhasbeendistilledthereshouldbelittleornosolidonthewatchglass,explainwhy.

Q1.Rock salt is a mixture of sand and salt.

Salt dissolves in water. Sand does not dissolve in water.

Some students separated rock salt.


1. Place the rock salt in a beaker. 2. Add 100 cm3 of cold water. 3. Allow the sand to settle to the bottom of the beaker. 4. Carefully pour the salty water into an evaporating dish. 5. Heat the contents of the evaporating dish with a Bunsen burner until salt crystals start to

form.

(a) Suggest one improvement to step 2 to make sure all the salt is dissolved in the water.

.............................................................................................................................

............................................................................................................................. (1)

(b) The salty water in step 4 still contained very small grains of sand.

Suggest one improvement to step 4 to remove all the sand.

.............................................................................................................................

............................................................................................................................. (1)

(c) Suggest one safety precaution the students should take in step 5.

.............................................................................................................................

............................................................................................................................. (1)

(d) Another student removed water from salty water using the apparatus in the figure below.

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Describe how this technique works by referring to the processes at A and B.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(e) What is the reading on the thermometer during this process?

........................................... °C (1)

(Total 6 marks)

GCSETrilogyrequiredpracticalactivity:SpecificheatcapacityYouareprovidedwiththefollowing:

• copperblockwrappedininsulation,withtwoholesforathermometerandheater

• thermometer

• pipettetoputwaterinthethermometerhole

• 30Wheater

• 12Vpowersupply

• insulationtowraparoundtheblocks

• ammeterandvoltmeter

• five4mmleads

• stopwatchorstopclock

• balance.

Readtheseinstructionscarefullybeforeyoustartwork.9. Measureandrecordthemassofthecopperblockinkg.10. Placeaheaterinthelargerholeintheblock.

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11. Connecttheammeter,powerpackandheaterinseries.12. Connectthevoltmeteracrossthepowerpack.

13. Usethepipettetoputasmallamountofoilintheotherhole.14. Putthethermometerinthishole.15. Switchthepowerpackto12V.Switchiton.16. Recordtheammeterandvoltmeterreadings.Theseshouldn’tchangeduringtheexperiment.17. Measurethetemperatureandswitchonthestopclock18. Recordthetemperatureeveryminutefor10minutes.19. Calculatethepoweroftheheaterinwatts.

Todothis,multiplytheammeterreadingbythevoltmeterreading.Power=currentxpotentialdifference

20. Calculatetheworkdonebytheheater.Todothis,multiplythetimeinsecondsbythepoweroftheheater.

Workdone(j)=powerxtime21. Repeatthisexperimentwithdifferentmaterials

Questions

IstheammeterconnectedinSeriesorParallel?

Whatistheammeterusedtomeasure?

IsthevoltmeterconnectedinSeriesorParallel?

Whatisthevoltmeterusedtomeasure?

Ifyoudonotinsulatethemetalblock,thevaluewecalculateforspecificheatcapacitywillbehigherthanthetruevalue.Explainwhythemeatalblockneedstobeinsulated.

V

A

12V

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Q1.(a) A student used the apparatus drawn below to investigate the heating effect of an electric heater.

(i) Before starting the experiment, the student drew Graph A.

Graph A shows how the student expected the temperature of the metal block to change after the heater was switched on.

Describe the pattern shown in Graph A.

...............................................................................................................

...............................................................................................................

...............................................................................................................

............................................................................................................... (2)

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(ii) The student measured the room temperature. He then switched the heater on and measured the temperature of the metal block every 50 seconds.

The student calculated the increase in temperature of the metal block and plotted Graph B.

After 300 seconds, Graph B shows the increase in temperature of the metal block is lower than the increase in temperature expected from Graph A.

Suggest one reason why.

...............................................................................................................

............................................................................................................... (1)

(iii) The power of the electric heater is 50 watts.

Calculate the energy transferred to the heater from the electricity supply in 300 seconds.

...............................................................................................................

...............................................................................................................

...............................................................................................................

Energy transferred = ........................................... J (2)

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(b) The student uses the same heater to heat blocks of different metals. Each time the heater is switched on for 300 seconds.

Each block of metal has the same mass but a different specific heat capacity.

Metal Specific heat capacity in J/kg°C

Aluminium 900

Iron 450

Lead 130

Which one of the metals will heat up the most?

Draw a ring around the correct answer.

aluminium Iron lead

Give, in terms of the amount of energy needed to heat the metal blocks, a reason for your answer.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

(Total 7 marks)

2. A student investigated the specific heat capacity of metals.

(a) Describe an experiment the student could do to measure the specific heat capacity of a metal.

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(b) The student calculated the specific heat capacity of four metals.

The table below shows the student’s results. Metal

Mass of material

in kg Time in minutes

Temperature chan

ge in °C

Change in thermal energy

in J

Calculated specific

heat capacity of material

in J / kg °C

Aluminium

1 10 2 4 780 2 390

Brass 1 10 4 4 660 1 165

Copper 1 10 4 600 657

Steel 1 10 5 4 690 938

Use data from the table above to calculate the temperature change for copper.

Use the correct equation from the Physics Equation Sheet.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

Temperature change = ................................ °C (3)

(c) What is the independent variable in the student’s investigation?

Tick one box.

Mass of material

Power used

Time in minutes

Type of material

(1)

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(d) The student calculated the specific heat capacity of aluminium to be 2390 J / kg °C.

The ‘true’ specific heat capacity of aluminium is 900 J / kg °C.

Suggest why the student’s result for aluminium is different from the ‘true’ value.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

(e) The teacher suggested that putting bubble wrap round the metal block would change the results.

How would using bubble wrap change the results?


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........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

(Total 14 marks)

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GCSEPhysicsrequiredpracticalactivity3:Resistance


Usecircuitdiagramstosetupanappropriatecircuittoinvestigateafactor/thefactorsthataffecttheresistanceofanelectricalcircuit.Thisshouldinclude:

•thelengthofawireatconstanttemperature

•combinationsofresistorsinseriesandparallel.

AT1,AT6,AT7

Activity3:Investigatinghowtheresistanceofawirevarieswithitslength

Adimmerswitchallowsyoutocontrolthebrightnessofalamp.

Youwillinvestigatehowthedimmerswitchworks.Youwillconstructacircuittomeasurethepotentialdifferenceacrossawireandthecurrentinthewire.Youwilldothisfordifferentlengthsofwire.

Method


• abatteryorsuitablepowersupply

• ammeterormultimeter

• voltmeterormultimeter

• crocodileclips

• resistancewireegconstantan

• connectingleads.

1. Readtheseinstructionscarefullybeforeyoustartwork.

2. Setupthecircuitasshowninthediagram

3. Connecta10cmlengthofwireusingthecrocodileclips4. Recordthecurrentandpotentialdifferenceofthe10cmlengthofwire5. Usevoltage/currenttocalculateresistance6. Repeatforlengths20-80cm

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Recordinatablethe:

• length of the wire between the crocodile clips

• the readings on the ammeter

• the readings on the voltmeter.

Youwillneedfourcolumnsintotal.

Lengthofwireincm

PotentialdifferenceinV

CurrentinA

ResistanceinW

.

1. Calculate and record the resistance for each length of wire using the equation:

resistanceinW =potentialdifferenceinV

currentinA


• ‘Resistance in W’ on the y-axis

• ‘Length of wire in cm’ on the x-axis.

3. You should be able to draw a straight line of best fit although it may not go through the origin.

Questions

• What is the independent variable?

• What is the range of the independent variable?

• What is the dependent variable?

• What are the control variables?

• How do you connect an ammeter?

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• How do you connect a voltmeter?

• If you connected your ammeter and it had a reading of 0.02 A even with the powerpack switched off, what kind of error would this be called? Explain what you could do to prevent this error from affecting your results.

Q1.(a) A resistor is a component that is used in an electric circuit.

(i) Describe how a student would use the circuit to take the readings necessary to determine the resistance of resistor R.

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Q2.(a) The diagram shows the circuit used to investigate the resistance of a sample of a material. The diagram is not complete; the ammeter and voltmeter are missing.

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(i) Draw the symbols for the ammeter and voltmeter on the diagram in the correct places.

(2)

(ii) How can the current through the material be changed?

...............................................................................................................

............................................................................................................... (1)

(b) The material, called conducting putty, is rolled into cylinders of different lengths but with equal thickness. Graph 1 shows how the resistance changes with length.

Length in centimetres

(i) The current through a 25 cm length of conducting putty was 0.15 A.

Use Graph 1 to find the resistance of a 25 cm length of conducting putty.

Resistance = .................................................. ohms

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(1)

(ii) Use your answer to (b) (i) to calculate the potential difference across a 25 cm length of conducting putty.

Show clearly how you work out your answer.

...............................................................................................................

...............................................................................................................

...............................................................................................................

Potential difference = .................................................. volts (2)

(c) A second set of data was obtained using thicker pieces of conducting putty. Both sets of results are shown in Graph 2.

Length in centimetres

(i) What is the relationship between the resistance and the thickness of the conducting putty?

...............................................................................................................

............................................................................................................... (1)

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(ii) Name one error that may have reduced the accuracy of the results.

............................................................................................................... (1)

(Total 8 marks)

GCSETrilogyrequiredpracticalactivity:I-VCharacteristics


UsecircuitdiagramstoconstructappropriatecircuitstoinvestigatetheI-Vcharacteristicsofvarietyofcircuitelementsincludingafilamentlamp,adiodeandaresistoratconstanttemperature.

AT6,AT7

Therearethreeactivities.Ineachoneyouaregoingtomeasureelectriccurrentinacomponentasyouchangethepotentialdifference(Pd)acrossthecomponent

YouwillthenplotagraphofcurrentinanagainstpotentialdifferenceinV.Youwillinvestigatethebehaviourofaresistor,alampandadiode.

Method

1. Setuptheelectricalcircuitasshown.

2. Setthepowersupplytoalowvoltagesettinge.g.6V

3. Switchonthepowersupply.

4. Recordthecurrentandpotentialdifferencereadingsinasuitabletable.

5. Repeattheprocedurebyvaryingthecurrentusingthevariableresistor

A

V

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Nowrepeatthisprocedureforthesetwocircuitsalso:

Questions Draw the circuit symbol for a fixed resistor

Draw the circuit symbol for a diode Draw the circuit symbol for a filament bulb What is the circuit symbol for a variable resistor? How is the voltmeter connected? How is the ammeter connected? Explain why the variable resistor is included in the circuit. Sketch the shape of the VI graph for a. Fixed Resistor b. filament bulb c. diode

A

V

mA

V

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Q1.A student wants to investigate how the current through a filament lamp affects its resistance.

(a) Use the circuit symbols in the boxes to draw a circuit diagram that she could use.

12 V battery

variable resistor

filament lamp voltmeter ammeter

(2)

(b) Describe how the student could use her circuit to investigate how the current through a filament lamp affects its resistance.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (4)

(c) The student’s results are shown in Figure 1.

Figure 1

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Describe how the resistance of the filament lamp changes as the current through it increases.

.............................................................................................................................

............................................................................................................................. (1)

(d) Use Figure 1 to estimate the resistance of the filament lamp when a current of 0.10 A passes through the lamp.

Resistance = .......................................... Ω (1)

(e) The current-potential difference graphs of three components are shown in Figure 2.

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Use answers from the box to identify each component.

diode filament lamp light dependent resistor

resistor at constant temperature thermistor

Figure 2

....................................................

....................................................

.................................................... (3)

(Total 11 marks)

Q2.Electrical circuits have resistance.

(a) Draw a ring around the correct answer to complete the sentence.

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When the resistance of a circuit increases, the current in the circuit

decreases.

increases.

stays the same.

(1)

(b) Use the correct answer from the box to complete each sentence.

a filament bulb an LED an LDR

An electrical component which has a resistance that increases as the

temperature increases is .................................................. .

An electrical component which emits light only when a current flows through it

in the forward direction is .................................................. . (2)

(c) When some metals are heated the resistance of the metal changes.

The equipment for investigating how the resistance of a metal changes when it is heated is shown in the diagram.

In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

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Describe an investigation a student could do to find how the resistance of a metal sample varies with temperature. The student uses the equipment shown.

Include in your answer:

• how the student should use the equipment

• the measurements the student should make

• how the student should use these measurements to determine the resistance

• how to make sure the results are valid.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

......................................................................................................................... (6)

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(d) The table shows some data for samples of four metals P, Q, R and S.

The metal samples all had the same cross-sectional area and were the same length.

Metal sample Resistance at

0°C in ohms

Resistance at 100°C in ohms

P 4.05 5.67

Q 2.65 3.48

R 6.0 9.17

S 1.70 2.23

A graph of the results for one of the metal samples is shown.

Temperature in °C

(i) Which metal sample, P, Q, R or S, has the data shown in the graph? (1)

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(ii) One of the results is anomalous. Circle this result on the graph. (1)

(iii) Suggest a reason for the anomalous result.

................................................................................................................

................................................................................................................ (1)

(iv) The same equipment used in the investigation could be used as a thermometer known as a ‘resistance thermometer.’

Suggest two disadvantages of using this equipment as a thermometer compared to a liquid-in-glass thermometer.

1 .............................................................................................................

................................................................................................................

2 .............................................................................................................

................................................................................................................ (2)

(Total 14 marks)

Q3.A student investigated how current varies with potential difference for two different lamps.

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Her results are shown in the figure below.

(a) Complete the circuit diagram for the circuit that the student could have used to obtain the results shown in the figure above.

(3)

(b) Which lamp will be brighter at any potential difference?


Use the figure above to aid your explanation

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(c) Lamp B has the higher resistance at any potential difference.

Explain how the figure above shows this.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

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............................................................................................................................. (2)

(d) Both lamps behave like ohmic conductors through a range of values of potential difference.

Use the figure above to determine the range for these lamps.


.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (3)

(Total 10 marks)

GCSETrilogyrequiredpracticalactivity:Density


Useappropriateapparatustomakeandrecordthemeasurementsneededtodeterminethedensitiesofregularandirregularsolidobjectsandliquids.

Volumeshouldbedeterminedfromthedimensionsofregularlyshapedobjectsandbyadisplacementtechniqueforirregularlyshapedobjects.

Dimensionstobemeasuredusingappropriateapparatussuchasaruler,micrometreorVerniercallipers.

AT1

Identifyingasubstancefromitsdensity.

Therearethreeactivities.Ineachoneyouaregoingtomeasurethedensityofanobject.Youwillthenusethisvaluetofindoutwhatthesubstanceis.Youwillbeexpectedtoworkasaccuratelyaspossible.

Activity1:youwilldeterminethedensityofaregularshapedobjectusingarulerandbalance.

Activity2:youwillmeasurethemassofanobjectinthesamewayasactivity1.Youwillalsomeasureitsvolumefromtheamountofwateritdisplaces.Activity3:youwillfindthedensityofaliquid.

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Method

Activity1:Regularshapedobjects


• 30cmrulermarkedoffinmm

• digitalbalance

• regularshapedobjects.

1. Foreachobjectmeasurethe:

• length

• width

• height.

2. Recordyourresultsinatable.

Includecolumnsforvolume,mass,densityandsubstance.

• volume

• mass

• density

• substance.

3. Measurethemassofeachobjectusingthedigitalbalance.Recordtheresults.4. Calculateandrecordthevolumes(length´width´height).5. Calculateandrecordthedensities(mass÷volume).6. Usethetablebelowtoidentifythesubstanceeachobjectismadefrom.

Substance Aluminium Zinc Iron Copper Gold

Densitying/cm3 2.7 7.1 7.9 8.9 19.3

Activity2: Irregularshapedobjects.


• digitalbalance

• displacementcanandsomethingtostanditon(egabrick)

• variousmeasuringcylinders

• beakerofwaterandanextraemptybeaker

• papertowels

• cottonorthinstring

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• irregularlyshapedobjects.1. Measurethemassofoneoftheirregularshapedobjects.2. Recordyourresultinatable.

Itwillneedcolumnsfor:

• volume

• density

• mass

• substance.

3. Placeadisplacementcanonabrick.Putanemptybeakerunderthespoutandfillthecanwithwater.Watershouldbedrippingfromthespout.

4. Waituntilthewaterstopsdripping.Thenplaceameasuringcylinderunderthespoutinsteadofthebeaker.Choosethemeasuringcylinderyouthinkwillgivethemostprecisereading.

5. Tietheobjecttoapieceofcotton.Verycarefullyloweritintothedisplacementcansothatitiscompletelysubmerged.

Collectallofthewaterthatcomesoutofthespoutinthemeasuringcylinder.

6. Measureandrecordthevolumeofthecollectedwater.Thisvolumeisequaltothevolumeoftheobject. 7. Calculateandrecordthedensityoftheobject.

Trytofindoutwhatsubstanceitismadefrom.8. Repeatsteps1‒7forsomeotherobjects.

Remembertorefillthecaneachtime.

Activity3–liquid

Youareprovidedwiththefollowing

• digitalbalance

• 250mlbeaker

• 100mlmeasuringcylinder

• suitableliquidegsugarsolution.

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1. Measurethemassoftheemptybeaker.

2. Recordyourresultsinatable.

Yourtablewillneedcolumnsforthe:

• massoftheemptybeaker

• massofthebeakerwiththeliquidin

• massoftheliquid

• volumeoftheliquid

• densityoftheliquid.

3. Pourabout100mlofliquidintothemeasuringcylinder.Measureandrecordthevolume.4. Pourthisliquidintothebeaker.Measureandrecordthemassofthebeakerandliquid.5. Calculateandrecordthevolumeoftheliquid.6. Calculatethedensityoftheliquid.7. Thedensityofwateris1g/cm3.8. Determinethemassofsugarpercm3dissolvedinthewater.Assumethesugardoesnotaffectthevolumeof

thewater. Questions

Q1.A student wants to calculate the density of the two objects shown in the figure below.

© Whitehoune/iStock/Thinkstock, © Marc Dietrich/Hemera/Thinkstock

Describe the methods that the student should use to calculate the densities of the two objects.

.................................................................................................................................

.................................................................................................................................

.................................................................................................................................

.................................................................................................................................

.................................................................................................................................

.................................................................................................................................

.................................................................................................................................(Total 6 marks)

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GCSETrilogyrequiredpracticalactivity:Forceandextension


Investigatetherelationshipbetweenforceandextensionforaspring. AT1,AT2

Makingandcalibratingaspringbalance(newtonmeter)

Youwillinvestigatetherelationshipbetweentheweighthungfromaspringandhowmuchlongerthespringgets(theextension).

Youwilluseyourresultstoplotagraphofextensionagainstweight.Thenyouwilluseyourgraphtofindtheweightofamysteryobject.

Method


• aspring

• ametreruler

• asplintandtapetoactasapointer

• a10Nweightstack

• aclampstand,withtwoclampsandbosses

• aheavyweighttopreventtheapparatustippingover

• amysteryobjecttoweigh.

1. Attachthetwoclampstotheclampstandusingthebosses.Thetopclampshouldbefurtheroutthanthelowerone.

2. Placetheclampstandneartheedgeofabench.Theendsoftheclampsneedtostickoutbeyondthebench.3. Placeaheavyweightonthebaseoftheclampstandtostoptheclampstandtippingover.

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4. Hangthespringfromthetopclamp.5. Attachtherulertothebottomclampwiththezeroonthescaleatthetopoftheruler.

Iftherearetwoscalesgoinginoppositedirections,youwillhavetoremembertoreadtheonethatincreasesgoingdown.

6. Adjusttherulersothatitisvertical.Thezeroonthescaleneedstobeatthesameheightasthetopofthespring.

7. Attachthesplintsecurelytothebottomofthespring.Makesurethatthesplintishorizontalandthatitrestsagainstthescaleoftheruler.

8. Takeareadingontheruler–thisisthelengthoftheunstretchedspring.9. Carefullyhookthebaseoftheweightstackontothebottomofthespring.Thisweighs1.0newton(1.0N).10. Takeareadingontheruler–thisisthelengthofthespringwhenaforceof1.0Nisappliedtoit.11. Addfurtherweights.Measurethelengthofthespringeachtime.12. Recordyourresultsinatablesuchastheonebelow.Youwillneedathirdcolumnfortheextension.Thisisthe

amountthestringhasstretched.Tocalculatethisyousubtractthelengthoftheunstretchedspringfromeachofyourlengthreadings.

WeightinN Lengthofspringincm Extensionofspringincm

13. Donotputtheapparatusawayyet.14. Plotagraphwith:

• ‘Extensionofspringincm’onthey-axis

• ‘WeightinN’onthex-axis.Hangtheunknownobjectonthespring.Measuretheextensionanduseyourgraphtodeterminetheobject’sweight.Checkitwithanewtonmeter.

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Questions

Whataretheunitsofweight?

Whataretheunitsofmass?

Explainhowyouwillcalculatetheextensionofthespring?

Thisexperimentwillonlyworkupuntilthelimitofproportionality,explainwhatthismeans.

Q1.A student suspended a spring from a laboratory stand and then hung a weight from the spring.

Figure 1 shows the spring before and after the weight is added.

Figure 1

(a) Which distance gives the extension of the spring?

Tick one box.

from J to K

from K to L

from J to L

(1)

(b) The student used the spring, a set of weights and a ruler to investigate how the extension of the spring depended on the weight hanging from the spring.

Figure 2 shows that the ruler is in a tilted position and not upright as it should be.

Figure 2

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How would leaving the ruler tilted affect the weight and extension data to be recorded by the student?

Use answers from the box to complete each sentence.

Each answer may be used once, more than once or not at all.

greater than the same as smaller than

The weight recorded by the student would be .......................................... the actual weight.

The extension recorded by the student would be .......................................... the actual weight.

(2)

(c) The student moves the ruler so that it is upright and not tilted.

The student then completed the investigation and plotted the data taken in a graph.

The student’s graph is shown in Figure 3.

Figure 3

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Use Figure 3 to determine the additional force needed to increase the extension of the spring from 5cm to 15cm.

Additional force = ............................................ N (1)

(d) What can you conclude from Figure 3 about the limit of proportionality of the spring? (1)

(e) The student repeated the investigation with three more springs, K, L and M.

The results for these springs are given in Figure 4.

Figure 4

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All three springs show the same relationship between the weight and extension.

What is that relationship?

Tick one box.

The extension increases non-linearly with the increasing weight.

The extension is inversely proportional to the weight.

The extension is directly proportional to the weight.

(1)

(f) Which statement, A, B or C, should be used to complete the sentence?

Write the correct letter, A, B or C, in the box below.

A a lower spring constant than

B the same spring constant as

C a greater spring constant than

From Figure 4 it can be concluded that spring M has the other two springs. (1)

(Total 7 marks)

Q2.A student suspended a spring from a laboratory stand and then hung a weight from the spring.

Figure 1 shows the spring before and after the weight is added.

Figure 1

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(a) Measure the extension of the spring shown in Figure 1.

Extension = ............................................... mm (1)

(b) The student used the spring, a set of weights and a ruler to investigate how the extension of the spring depended on the weight hanging from the spring.

Before starting the investigation the student wrote the following prediction:

The extension of the spring will be directly proportional to the weight hanging from the spring.

Figure 2 shows how the student arranged the apparatus.

Figure 2

Before taking any measurements, the student adjusted the ruler to make it vertical.

Explain why adjusting the ruler was important.

.............................................................................................................................

.............................................................................................................................

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.............................................................................................................................

............................................................................................................................. (2)

(c) The student measured the extension of the spring using a range of weights.

The student’s data is shown plotted as a graph in Figure 3.

Figure 3

What range of weight did the student use?

............................................................................................................................. (1)

(d) Why does the data plotted in Figure 3 support the student’s prediction?

.............................................................................................................................

............................................................................................................................. (1)

(e) Describe one technique that you could have used to improve the accuracy of the measurements taken by the student.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (2)

(f) The student continued the investigation by increasing the range of weights added to the spring.

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All of the data is shown plotted as a graph in Figure 4.

Figure 4

At the end of the investigation, all of the weights were removed from the spring.

What can you conclude from Figure 4 about the deformation of the spring?

.............................................................................................................................

.............................................................................................................................

Give the reason for your conclusion.

.............................................................................................................................

............................................................................................................................. (2)

(Total 9 marks)

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GCSETrilogyrequiredpracticalactivity:Acceleration


Investigatetheeffectofvaryingtheforceontheaccelerationofanobjectofconstantmassandtheeffectofvaryingthemassofanobjectontheaccelerationproducedbyaconstantforce.

AT1,AT2,AT3

Investigatingaccelerationusinganairtrackandlightgates.

Youwillinvestigatetherelationshipbetweentheaccelerationofanobjectandthesizeoftheforceactinguponit.

Youwilluseanairtrack.Thisproducesacushionofairwhichallowsgliderstomovealmostfrictionfree.


• linearairtrackandgliders

• vacuumcleaner

• benchpulley,stringandsmallweightstackeg1Ninstepsof0.2N

• card

• twoclampstands,withclampsandbosses

• twolightgates,interfaceandcomputer

• Adhesiveputtytoattachtheweightstotheglider.

1. Placetheairtrackonabenchandattachittothevacuumcleaner,seton‘blow’.2. Placeagliderontheairtrackandswitchonthevacuumcleaner.Theglidershouldliftupofftheairtrackand

befreetomove.3. Adjustthelegsoftheairtracksothattheglidermoveswithouttouchingandtheairtrackishorizontal.

Therearetwoseparateadjustmentstomake.Withthevacuumcleaneron:

• placethegliderabovetheadjusterthattiltstheairtrackfromsidetoside.Adjustthelengthoftheleguntilthegliderdoesnottouchthesides

• placethegliderinthemiddleoftheairtrack.Adjusttheotherleguntilthegliderdoesnotmovewhenreleased.

4. Cutoutapieceofcardmeasuring5cm´20cm.Putitinthegrooveontheglider.Thelongsideshouldbehorizontal.

5. Clampthetwolightgateshorizontally.Positionthemabovetheairtracksothatthecardpassesthroughthemastheglidermoves.

6. Connectthelightgatestotheinterfaceandcomputer.Startthesoftwarefortiming.

Youshouldhavetheopportunitytochooseaccelerationusingtwolightgates.

Typeinthelengthofthecard(20cm)whenaskedbythecomputer.

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7. Checkthemovementofthegliderbygentlypushingitalongthetrack.Thesoftwareneedstobeon.Theaccelerationshouldbeclosetozero.Switchoffthevacuumcleaner.

8. Attachthebenchpulleytotheendoftheairtrackawayfromthevacuumcleaner.9. Tiealengthofstringtotheglider.Passthestringoverthepulleyandattachtheweightstacktotheotherend

ofthestring.

Makesurethestringishorizontalandisinlinewiththeairtrack.10. Switchonthevacuumcleaner.Theglidershouldacceleratethroughthelightgatesastheweightfallstothe

ground.11. Ifnecessary,movethesecondlightgatesothatthegliderpassesthroughitbeforetheweighthitstheground.

Iftheweighthitsthegroundtooearly,thegliderwillstopacceleratingtooearly.

12. The first experiment will investigate how the acceleration depends upon the force. The force is provided by the weight stack.

• Attach the full weight stack (1 N) to the end of the string.

• Switch on the software.

• Make sure the glider is in position and switch on the vacuum cleaner.

• The glider should accelerate through the light gates towards the bench pulley.

• Record the acceleration. Repeat.

• If the two values are not similar, repeat again.

• Record your readings in a table such as the one below. Calculate the mean.

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ForceinN

Accelerationincm/s2

Firstreading SecondreadingThirdreading(ifnecessary)

Mean

13. Remove one weight (0.2 N) and attach that to the glider. This will keep the total mass constant. (The

weight stack is being accelerated too.)

14. Repeat the experiment for a force of:

• 0.8 N

• 0.6 N

• 0.4 N

• 0.2 N. Remember to attach each weight to the glider as it is removed from the weight stack.


• ‘Acceleration in m/s2’ on the y-axis

• ‘Force in N’ on the x-axis.

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Questions

Whatistheindependentvariable?

Whatistherangeoftheindependentvariable?

Whatisthedependentvariable?

WhatistheintervalbetweentheForcesused?

Explainhowyoucalculateameanvalue.

Explainwhycalculatingameanvalueisuseful?

GCSETrilogyrequiredpracticalactivity:Waves

Required practical activity Apparatus and techniques

Make observations to identify the suitability of apparatus to measure the frequency, wavelength and speed of waves in a ripple tank and waves in a solid and take appropriate measurements.

AT 4

Theactivityissplitintotwoparts:

• observingwaterwavesinarippletank

• observingwavesonastretchedstringorelasticcord.

Activity1:Observingwavesinarippletank


• rippletankplusaccessories

• suitablelowvoltagepowersupply

• metreruler.

1. Setuptherippletank.

Alargesheetofwhitecardorpaperneedstobeonthefloorunderthetank.

2. Pourwatertoadepthofabout5mmintothetank.

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3. Adjusttheheightofthewoodenrodsothatitjusttouchesthesurfaceofthewater.4. Switchonboththeoverheadlampandtheelectricmotor.5. Adjustthespeedofthemotor.Lowfrequencywaterwavesneedtobeproduced.6. Adjusttheheightofthelamp.Thepatternneedstobeclearlyseenonthecardonthefloor.7. Placeametreruleratrightanglestothewavesshowninthepatternonthecard.

Measureacrossasmanywavesaspossible.Thendividethatlengthbythenumberofwaves.Thisgivesthewavelengthofthewaves.

8. Countthenumberofwavespassingapointinthepatternoveragiventime(say10seconds).

Thendividethenumberofwavescountedby10.Thisgivesthefrequencyofthewaves.

9. Calculatethespeedofthewavesusingtheequation:

wavespeed=frequency´wavelength

Activity2:Observingwavesonastretchedstringorelasticcord.


• vibrationgenerator

• suitablepowersupply(variablefrequency)

• suitablestringorelasticatedcord

• setof100gmassesandhanger

• setof10gmassesandhanger

• woodenbridge

• pulleyonaclamp.

1. Setuptheapparatusasshown.

2. Switchonthevibrationgenerator.Thestring(orelasticatedcord)shouldstarttovibrate.3. Aclearwavepatternneedstobeseen.Todothis,adjustthetensioninthestringormovethewoodenbridge

toadjustthelengthofthestring.

Thewavesshouldlookliketheyarestationary.

4. Useametrerulertomeasureacrossasmanyhalfwavelengthsaspossible(ahalfwavelengthisoneloop).

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Thendividethetotallengthbythenumberofhalfwaves.Multiplyingthisnumberbytwowillgivethewavelength.

5. Thefrequencyisthefrequencyofthepowersupply.

6. Calculatethespeedofthewaveusingtheequation:wavespeed=frequency´wavelength

Questions

Whataretheunitsofwavespeed?

Whataretheunitsofwavelength?

Whataretheunitsoffrequency?

Drawadiagramofawaveandlabelthewavelength.

If15wavespassapointin10secondswhatisthefrequency?

If2wavespassapointin4secondswhatisthefrequency?

Q1. (a) A swimming pool has a wave making machine. The diagram shows the water wave pattern for 3 seconds.

(i) How many water waves are shown in the diagram?

................................................................................................................... (1)

(ii) What is the frequency of the water waves?

................................................................................................................... (1)

(iii) Which one of the units below is used to measure frequency? Underline your answer.

hertz joule watt (1)

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(b) The diagram shows the direction of the waves across the pool. The waves reflect off the side of the pool.

Draw a line on the diagram to show the direction of the waves after they hit the side of the pool.

(1)

(c) The swimming pool is used to test a model of an electricity generator. The waves make the floating generator move up and down. This energy is transferred to electricity.

(i) In the following sentence, cross out the two lines that are wrong in the box.

The diagram shoes that the amplitude of the waves as the waves pass the generator.

(1)

(ii) What type of energy does the generator transfer to electricity?

................................................................................................................... (1

(iii) Energy from ocean waves could be used to generate electricity. Would this be a renewable or non-renewable energy resource?

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................................................................................................................... (1)

(Total 7 marks)

Q2. The diagram shows a water wave drawn to scale.

(a) What is the wavelength of this water wave? ............................... cm (1)

(b) What is the amplitude? ............................... cm (1)

(c) Twelve waves pass an observer in four seconds.

What is the frequency of the waves? Show clearly how you work out your answer and give the unit.

.............................................................................................................................

.............................................................................................................................

Frequency = ..................................................................... (3)

(Total 5 marks)

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Q3. The diagram shows a wave travelling along a rope.

(a) On the diagram:

(i) show the wavelength and label it W;

(ii) show the amplitude and label it A. (2)

(b) The wavelength of the wave is 0. I m. Its frequency is 2 Hz.

Calculate the speed of the wave. Show clearly how you work out your answer and give the unit.

.............................................................................................................................

.............................................................................................................................

.............................................................................................................................

Speed of wave ................................................................. (3)

(Total 5 marks)

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GCSEPhysicsrequiredpracticalactivity:Radiationandabsorption


Investigatehowtheamountofinfraredradiationabsorbedorradiatedbyasurfacedependsonthenatureofthatsurface.

AT1,AT4

Investigatingtheamountofinfra-redradiationemittedbydifferentsurfaces


• Lesliecube• kettle

• infrareddetector

• heatproofmat.1. Place the Leslie cube on to a heat proof mat. 2. Fill the cube with very hot water and replace the lid of the cube.

3. Use the detector to measure the amount of infrared radiated from each surface.

Make sure that before a reading is taken the detector is the same distance from each surface.

Draw a bar chart to show the amount of infrared radiated against the type of surface.

Questions

1. Whatistheindependentvariable?2. Whatisthedependentvariable?3. Giveexamplesofcontrolvariables4. Whichsurfacewillemitthemostinfraredradiation?Explainyouranswer.5. Foreachsurface3readingsweretakenusinganinfraredprobe.Seethetablebelow.

Colourofsurface

TemperatureofthesurfaceoC1 2 3 Mean

black 87.9 87.8 88.1 silver 23.3 24.5 53.2

5a.Calculatethemeanvalueforeachsurface.

5b.Whatistheresolutionoftheinfraredprobe?

Q1. The diagram shows the equipment a student used to investigate how the colour of a

Infrareddetector

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surface affects how fast it emits (gives out) heat.

An equal volume of boiling water was poured into each metal can. The student then recorded the temperature of the water in each can every minute for ten minutes.

(a) (i) Which of the following was a control variable in this investigation?

Put a tick ( ) in the box next to your answer.

The volume of boiling water.

The decrease in temperature of the water.

The outside colour of the metal can.

(1)

(ii) Give one advantage of using a temperature sensor and datalogger rather than a thermometer to measure the temperature of the water.

...............................................................................................................

............................................................................................................... (1)

(b) The student’s results for both cans are plotted on the graph.

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Which line, A or B, shows how the temperature of the water inside the black-coloured metal can changed?

Draw a ring around your answer. A B

Explain the reason for your answer.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................ (2)

(c) Some gardeners make soil darker by digging black soot into the soil. Other gardeners use straw to protect plants from the cold.

(i) Complete the following sentence by drawing a ring around the correct line in the box.

On a warm day, the temperature of darker coloured soil will increase

slower than

as fast as the temperature of lighter coloured soil.

faster than

(1)

(ii) Give a reason for your answer to part (c)(i).

...............................................................................................................

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............................................................................................................... (1)

(iii) The statement in the box is false.

Straw keeps plants warm by trapping air. This is because air is a good conductor.

Change one word in the statement to make the statement true.

Write down your new statement. The answer has been started for you.

This is because air is a ............................................................................ (1)

(Total 7 marks)

Q2.All objects emit and absorb infrared radiation.

(a) Use the correct answer from the box to complete each sentence.

dark matt dark shiny light matt light shiny

The best emitters of infrared radiation have

......................................................................... surfaces.

The worst emitters of infrared radiation have

......................................................................... surfaces. (2)

(b) Diagram 1 shows a sphere which is at a much higher temperature than its surroundings.

Diagram 1

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Energy is transferred from the sphere to the surroundings.

The table shows readings for the sphere in three different conditions, A, B and C.

Condition Temperature of sphere in °C

Temperature of surroundings in °C

A 70 5

B 80 0

C 90 30

In each of the conditions, A, B and C, the sphere transfers energy to the surroundings at a different rate.

Put conditions A, B and C in the correct order.


.........................................................................................................................

......................................................................................................................... (2)

(c) Diagram 2 shows a can containing water.

A student investigates how quickly a can of water heats up when it is cooler than room temperature.

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Diagram 2

The student has four cans, each made of the same material, with the following outer surfaces.

dark matt dark shiny light matt light shiny

The student times how long it takes the water in each can to reach room temperature.

Each can contains the same mass of water at the same starting temperature.

(i) Which can of water will reach room temperature the quickest?


................................................................................................................

................................................................................................................

................................................................................................................

................................................................................................................ (2)

(ii) Apart from material of the can, mass of water and starting temperature, suggest three control variables for the student’s investigation.

1 ............................................................................................................

................................................................................................................

2 ............................................................................................................

................................................................................................................

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3 ............................................................................................................

................................................................................................................ (3)

(d) The photographs show two different foxes.

Fox A Fox B

By Algkalv (Own work) [CC-BY-3.0], © EcoPic/iStock

via Wikimedia Commons

Which fox is better adapted to survive cold conditions?

Give reasons for your answer.

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

.........................................................................................................................

......................................................................................................................... (3)

(Total 12 marks)

Q3. A student investigated the effect of shape and colour on heat transfer.

The student used metal containers with the same volume but with different shapes and outside colour. The containers were each filled with water at 100 °C.

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After 20 minutes the temperature of the water inside each container was measured.

A

B

C

D

The results from the investigation are given in the table.

Container Colour Temperature after 20 minutes in °C

Temperature fall in °C

A White 86 14

B Black 86 14

C White 73 27

D Black 60 40

(i) The student uses the results in the table to see if shape has affected heat transfer.

Which containers should the student compare to do this?

...............................................................................................................


...............................................................................................................

............................................................................................................... (1)

(ii) Explain why the temperature of the water in both containers A and B fell by the same amount.

...............................................................................................................

...............................................................................................................

...............................................................................................................

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............................................................................................................... (2)

(iii) A central heating system has several radiators joined together. The hot water goes from the boiler, through each radiator in turn and then back to the boiler for reheating.

Give one reason, other than appearance, why it might not be a good idea to paint radiators black.

...............................................................................................................

............................................................................................................... (1)

(Total 4 marks)

Q4. A student was asked to investigate the heat loss from two metal cans, L and M. The cans were identical except for the outside colour.

The student filled the two cans with equal volumes of hot water. He then placed the temperature sensors in the water and started the data logger. The computer used the data to draw the graph below.

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(a) Which one of the following is a categoric variable?

Put a tick ( ) in the box next to your answer.

the outside colour of the cans

the starting temperature of the hot water

the time

the volume of hot water

(1)

(b) For can L, state the temperature drop of the water:

(i) in the first two-minute interval

................................................................................................................... (1)

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(ii) in the second two-minute interval.

................................................................................................................... (1)

(c) In both cans the water cooled faster at the start of the investigation than at the end of the investigation. Why?

.............................................................................................................................

............................................................................................................................. (1)

(d) One can was black on the outside and the other can was white on the outside.

What colour was can L? ..............................................

Explain the reason for your answer.

.............................................................................................................................

.............................................................................................................................

............................................................................................................................. (3)

(Total 7 marks)

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