A-Level Chemistry

Summer Learning

(Double Science Version)

Name: ______________________

If you want to study Chemistry at A-level you really have to own your learning. It is important to care about your study as you will be an academic of that subject. This means doing some wider reading, making a point of reading articles related to chemistry, taking the opportunity to visit areas of scientific interest.

To really immerse yourself in the subject here is a list of activities that would be good to complete over the summer.

Read:

Join: https://isaacphysics.org/chemistry Visit:

https://wellcomecollection.org/

http://www.sciencemuseum.org.uk/visitmuseum/plan_your_visit/exhibitions/john-dalton-frs http://www.sciencemuseum.org.uk/visitmuseum/plan_your_visit/exhibitions/challenge_of_materials Follow:

@SellaTheChemist @TheRSC @FunSizeSuze @JenDtweeting @ThePurplePage

Periodic Tales – Hugh Aldersley-Williams

Uncle Tungsten – Oliver Sacks

Stuff Matters – Mark Miodownwik

Section A: Key Notes to get you prepared Specification at a glance AS and A-level Physical chemistry

Inorganic chemistry Organic chemistry

Atomic s tructure Amount of s ubs ta nce Bonding Ene rge tics Kine tics Chemical equilibria, Le Chatelier’s principle and Kc Oxida tion, re duction and redox equations

P e riodicity Group 2, the alkaline earth metals Group 7 (17), the halogens

Introduction to organic chemistry Alka ne s Ha loge noa lka ne s Alke ne s Alcohols Orga nic a na lys is

A-level only topics Physical chemistry Inorganic chemistry Organic chemistry The rmodynamics Ra te e qua tions Equilibrium constant Kp for homogeneous systems Ele ctrode pote ntia ls and electrochemical cells Acids a nd ba s e s

Properties of Period 3 elements and oxides Tra ns ition me ta ls Re a ctions of ions in aqueous solution

Optica l is ome rism Aldehydes and ketones Ca rboxylic a cids a nd derivatives Aroma tic chemis try Amine s P olyme rs Amino a cids , prote ins and DNA Orga nic s ynthe s is NMR s pe ctros copy Chroma togra phy

Section B: GCSE C3 Questions: It will be helpful if you can learn the content you missed out on and answer these questions http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/ http://www.bbc.co.uk/schools/gcsebitesize/science/triple_edexcel/ Q1.Electrolysis

(a) Some metal objects are electroplated to improve their appearance.

Give another reason why some metal objects are electroplated. (1)

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(b) Copper sulfate solution was electrolysed using copper electrodes.

The mass of each electrode was determined before it was placed in the solution.

The electrolysis was carried out for a period of time. The electrodes were removed, washed, dried and their masses redetermined.

The table shows the masses of the electrodes before and after electrolysis.

Explain these results.

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(c) In an electrolysis experiment, oxide ions, O2−, form oxygen gas, O2.

Write the balanced half equation for the reaction. (2)

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*(d) Sodium chloride is an ionic compound. It contains sodium ions, Na+, and chloride ions, Cl−.

When molten sodium chloride is electrolysed, sodium metal and chlorine gas are formed. Describe how the sodium ions and chloride ions in solid sodium chloride are converted into sodium and chlorine by electrolysis.

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(Total for question = 12 marks)

Q2. (a) The ions in sodium chloride solution are

sodium ions, Na+ chloride ions, Cl– hydrogen ions, H+ hydroxide ions, OH– Sodium chloride solution is electrolysed using a direct electric current. (i) Which of these ions will be attracted to the cathode during the electrolysis of sodium chloride solution?

Put a cross ( ) in the box next to your answer. (1)

A H+ ions only B H+ and Na+ ions C Cl– ions only D Cl– and OH– ions

(ii) Chlorine is one of the products of the electrolysis. The half-equation for the production of chlorine is

2Cl– → Cl2 + 2e Explain how the half-equation shows that chloride ions are oxidised.

(2) .............................................................................................................................................. .............................................................................................................................................. (iii) Suggest why the solution remaining at the end of the electrolysis is alkaline.

(1) .............................................................................................................................................. .............................................................................................................................................. (iv) The electrolysis of sodium chloride solution does not produce metallic sodium.

State what change you would make to the electrolyte to obtain metallic sodium. (1)

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(b) (i) When copper sulfate solution is electrolysed using inert electrodes, oxygen is formed at the positively charged anode. Explain how the oxygen is formed from ions in the solution.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) The other product is copper.

1.27 g of copper were produced in an experiment. Calculate the number of moles of copper, Cu, produced in this experiment. (Relative atomic mass: Cu = 63.5)

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

amount of copper produced =. . . . . . . . . . . . . . . . . .mol

(Total for Question = 8 marks)

Q3. Gases & Equilibria When nitrogen and hydrogen react to form ammonia, the reaction can reach a dynamic equilibrium.

(a) Explain what is meant by a dynamic equilibrium.

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(b) In industry, the reaction between nitrogen and hydrogen is affected by the conditions used. (i) The pressure used is 250 atmospheres. Explain how the use of a higher pressure would affect the equilibrium yield of ammonia.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) The reaction between nitrogen and hydrogen to form ammonia is exothermic. The temperature used is 450°C. Explain how the use of a lower temperature would affect the equilibrium yield of ammonia.

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(iii) Even at 450°C, the reaction is very slow. State what is used in industry to overcome this problem.

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(c) (i) Calculate the minimum volume of hydrogen required to completely convert 1000 dm3 of nitrogen into ammonia.

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volume of hydrogen =. . . . . . . . . . . . . . . . . .dm3 (ii) Ammonia is reacted with excess nitric acid, HNO3, to make ammonium nitrate, NH4NO3.

NH3 + HNO3 → NH4NO3 Calculate the mass of ammonium nitrate produced by the complete reaction of 34 g of ammonia. (Relative atomic masses H = 1.0, N = 14, O = 16)

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

mass of ammonium nitrate produced =. . . . . . . . . . . . . . . . .g

(Total for Question = 11 marks)

Q4.When nitrogen and hydrogen react to form ammonia, the reaction can reach a dynamic equilibrium.

In industry, the reaction between nitrogen and hydrogen is affected by the conditions used.

(i) The pressure used is 250 atmospheres. Explain how the use of a higher pressure would affect the equilibrium yield of ammonia.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (ii) The reaction between nitrogen and hydrogen to form ammonia is exothermic. The temperature used is 450°C. Explain how the use of a lower temperature would affect the equilibrium yield of ammonia.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. (iii) Even at 450°C, the reaction is very slow.

State what is used in industry to overcome this problem. (1)

.............................................................................................................................................. Q5.Gases and ammonia

(a) Hydrogen reacts with oxygen to form water vapour.

2H2(g) + O2(g) → 2H2O(g)

If 200 cm3 of hydrogen react completely with 100 cm3 of oxygen, what is the maximum volume of water vapour formed, if all volumes are measured at the same temperature and pressure? Put a cross ( ) in the box to show your answer.

(1)

A 100 cm3

B 200 cm3

C 300 cm3

D 400 cm3

(b) Zinc reacts with dilute hydrochloric acid to form zinc chloride and hydrogen.

Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

Calculate the maximum volume of hydrogen formed, at room temperature and pressure, when 13.0 g of zinc reacts completely with excess hydrochloric acid. (relative atomic mass: Zn = 65.0, 1 mol of any gas occupies 24 dm3 at room temperature and pressure)

(2)

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volume of hydrogen = ........................................................... dm3

(c) In industry, ammonia is produced by the Haber process.

(i) What is the source of the hydrogen used in the Haber process?

Put a cross ( ) in the box to show your answer. A air B reaction of zinc with dilute sulfuric acid C electrolysis of water D natural gas

(ii) When nitrogen reacts with hydrogen, the amount of ammonia gradually increases until it becomes constant.

Explain why the amount of ammonia remains constant.

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*(d) The reaction between nitrogen and hydrogen is exothermic.

If nitrogen and hydrogen were reacted at 90 atm pressure and 300 °C, without a catalyst, some ammonia would be formed eventually. In the Haber process a pressure of 150 atm and a temperature of 450 °C are used, in the presence of an iron catalyst. Explain, with reasons, why the Haber process conditions are better for the manufacture of ammonia.

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(Total for question = 12 marks) Q6. Organic Chemistry

* The table gives information about four substances, A, B, C and D.

The substances, in no particular order, are ethane, ethanoic acid, ethanol and ethene.

Identify substances A, B, C and D, explaining how you have used the information in the table to identify them.

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(Total for question = 6 marks) Q7. (a) Vegetable oils and fats are esters.

One of these oils is boiled with concentrated sodium hydroxide solution. The mixture is poured into concentrated sodium chloride solution. A white solid is formed. (i) What type of substance is the white solid? Put a cross ( ) in the box next to your answer.

(1) A alcohol B fat C polyester D soap

(ii) The white solid is formed in a mixture with a solution of other substances.

Describe how a pure sample of the white solid can be obtained from this mixture. (2)

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(b) Complete the sentence by putting a cross ( ) in the box next to your answer.

Liquid oils can be converted into solid fats by hydrogenation. In this reaction

(1) A a salt and water are formed B the liquid oil is reacted with oxygen gas C unsaturated molecules in the liquid oil become saturated D bonds are formed

Q8.The structure of a molecule of an ester, ethyl ethanoate, is shown.

(i) Give the molecular formula of this compound.

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

(ii) Write the word equation for the reaction of ethanol with another compound to form ethyl ethanoate and another product.

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(iii) A hazard from the ethyl ethanoate fact sheet is shown in the box.

Suggest why, despite this hazard, it is still safe to use ethyl ethanoate in sweets.

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Q9. Qualitative Analysis (a) Substance X is an ammonium salt.

(i) Complete the sentence by putting a cross ( ) in the box next to your answer. A test was carried out to find which anion is present in substance X. Dilute hydrochloric acid was added to a sample of substance X. There was effervescence and the gas given off turned limewater milky. The anion present in substance X is

(1) A carbonate ion, CO3

2– B chloride ion, Cl– C nitrate ion, NO3

– D sulfate ion, SO4

2–

(ii) Describe how sodium hydroxide solution can be used to show that ammonium ions are present in substance X.

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(b) Aluminium ions, Al3+, react with hydroxide ions in solution to give a white precipitate of aluminium hydroxide. Write the ionic equation for this reaction.

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

*(c) A technician found some colourless crystals of a substance left, unlabelled, in a beaker in a laboratory. She knew the substance was one of potassium sulfate, potassium iodide, sodium sulfate or sodium iodide. Explain how, using chemical tests, the technician could find out if the substance left in the beaker was potassium sulfate, potassium iodide, sodium sulfate or sodium iodide. You may include equations in your answer.

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(Total for Question = 12 marks)

Q10.Making sodium chloride

To make pure sodium chloride from sodium hydroxide solution and dilute hydrochloric acid, a titration has to be used.

(a) Ethanol is produced by fermentation of carbohydrates.

The equation for the reaction is

HCl(aq) + NaOH(aq) → NaCl(........) + H2O(........)

(a) Which state symbols follow NaCl and H2O to complete the equation? Put a cross ( ) in the box next to your answer.

(1)

(b) The reaction above is a neutralisation reaction.

Write the ionic equation for the reaction. (2)

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(c) When sodium hydroxide solution is titrated with dilute hydrochloric acid, an acid-base indicator is used. The hydrochloric acid is added from a burette to the sodium hydroxide solution in a conical flask. At the end point the indicator changes colour.

(i) Give the name of a suitable indicator to use in this titration.

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

(ii) State the colour change for this indicator at the end point. (1) from .......................... to .......................... (d) A sodium hydroxide solution was made up by dissolving 20.0 g of sodium hydroxide in water and making the volume of the solution up to 1.00 dm3. Calculate the concentration of sodium hydroxide, NaOH, in this solution in mol dm−3. (relative atomic masses: H = 1.00, O = 16.0, Na = 23.0)

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concentration = ..................................... mol dm−3

(e) In another experiment, a titration was carried out. 25.0 cm3 of 1.50 mol dm−3 sodium hydroxide solution, NaOH, was titrated with hydrochloric acid. The volume of the hydrochloric acid required to neutralise the sodium hydroxide solution was 30.0 cm3.

Calculate the concentration of the hydrochloric acid, HCl, in mol dm−3.

HCl + NaOH → NaCl + H2O

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concentration = ..................................... mol dm−3

(Total for question = 9 marks) Q11.Qualitative Analysis

(a) Three solids, A, B, and C, are analysed.

(i) Solid A is potassium iodide. A small amount of solid A is dissolved in water to form a solution. Describe the test to show that the solution of A contains iodide ions.

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(ii) Solid B is ammonium chloride.

Describe the test to show that solid B contains ammonium ions. (3)

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(iii) Solid C is dissolved in water.

When sodium hydroxide solution is added to the solution of C, a red-brown precipitate is formed. Complete the sentence by putting a cross ( ) in the box next to your answer. This test shows that the ion present in solid C is

(1) A copper, Cu2+ B iron(II), Fe2+ C iron(III), Fe3+ D sodium, Na+

(b) Sodium hydroxide solution can be used to test for aluminium ions and for calcium ions in solution.

Describe the results of these tests for aluminium ions and for calcium ions, explaining how the results distinguish between the two ions.

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(Total for question = 9 marks)

Q12. Titrations: Quantitative Analysis

Titration can be used to determine the exact amount of hydrochloric acid that reacts with a given amount of sodium hydroxide solution. HCl + NaOH → NaCl + H2O

(a) What type of reaction takes place when hydrochloric acid reacts with sodium hydroxide solution?

(1) Put a cross ( ) in the box next to your answer. A neutralisation B oxidation C precipitation D reduction (b) Suggest why universal indicator must not be used in titration experiments.

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

*(c) Sodium chloride solution can be made from dilute hydrochloric acid and sodium hydroxide solution. Describe a titration experiment to find the exact volume of hydrochloric acid needed to neutralise 25.0 cm3 of sodium hydroxide solution and how you would use this result to obtain pure, dry crystals of sodium chloride.

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(d) Sodium hydroxide solution is titrated with dilute hydrochloric acid. The results of the experiment are

volume of sodium hydroxide solution = 25.0 cm3 volume of 0.100 mol dm–3 hydrochloric acid used

(i) State the volume of hydrochloric acid that must be used to calculate the concentration of sodium hydroxide solution.

(1) volume of hydrochloric acid =. . . . . . . . . . . . . . . . . .cm3

(ii) In a different experiment, 25.0 cm3 of sodium hydroxide solution reacted with 23.2 cm3 of 0.100 mol dm–3 hydrochloric acid, HCl. Calculate the concentration of this sodium hydroxide solution, NaOH, in mol dm–3.

(3) NaOH + HCl → NaCl + H2O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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concentration of sodium hydroxide solution = . . . . . . . . . . . . . . . . .mol dm–3

(Total for Question = 12 marks)

Section C: These are A-level Questions that can be answered with background GCSE knowledge and a little research. Weblinks: http://www.chemguide.co.uk/ http://www.a-levelchemistry.co.uk/new-aqa-a-level-chemistry.html https://chemrevise.org/ http://www.physicsandmathstutor.com/chemistry-revision/a-level-aqa/

Q1.(a) Table 1 shows some data about fundamental particles in an atom. Table 1

Particle proton neutron electron

Mass / g 1.6725 × 10–24 1.6748 × 10–24 0.0009 × 10–24

(i) An atom of hydrogen can be represented as 1H

Use data from Table 1 to calculate the mass of this hydrogen atom.

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(ii) Which one of the following is a fundamental particle that would not be deflected by an electric field?

A electron

B neutron

C proton

Write the correct letter, A, B or C, in the box.

(1)

(b) A naturally occurring sample of the element boron has a relative atomic mass of 10.8. In this sample, boron exists as two isotopes, 10B and 11B

(i) Calculate the percentage abundance of 10B in this naturally occurring sample of boron.

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(ii) State, in terms of fundamental particles, why the isotopes 10B and 11B have similar chemical reactions.

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(c) Complete Table 2 by suggesting a value for the third ionisation energy of boron. Table 2

First Second Third Fourth Fifth

Ionisation energy / kJ mol–1 799 2420 25 000 32 800

(1)

(d) Write an equation to show the process that occurs when the second ionisation energy of boron is measured. Include state symbols in your equation.

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(e) Explain why the second ionisation energy of boron is higher than the first ionisation energy of boron.

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(Total 8 marks)

Q2.Which type of bond is formed between N and B when a molecule of NH3 reacts with a molecule of BF3?

A Ionic.

B Covalent.

C Co-ordinate.

D Van der Waals.

(Total 1 mark)

Q3.What is the formula of calcium nitrate(V)?

A CaNO3

B Ca(NO3)2

C Ca2NO2

D Ca(NO2)2

(Total 1 mark)

Q4.In 2009 a new material called graphane was discovered. The diagram shows part of a model of the structure of graphane. Each carbon atom is bonded to three other carbon atoms and to one hydrogen atom.

(a) Deduce the type of crystal structure shown by graphane.

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(b) State how two carbon atoms form a carbon–carbon bond in graphane.

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(c) Suggest why graphane does not conduct electricity.

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(d) Deduce the empirical formula of graphane.

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(Total 4 marks)

Q5.The table shows some data about the elements bromine and magnesium.

Element Melting point / K Boiling point / K

Bromine 266 332

Magnesium 923 1383

In terms of structure and bonding explain why the boiling point of bromine is different from that of magnesium. Suggest why magnesium is a liquid over a much greater temperature range compared to bromine.

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Q6.Which of the following contains the most chloride ions?

A 10 cm3 of 3.30 × 10−2 mol dm−3 aluminium chloride solution

B 20 cm3 of 5.00 × 10−2 mol dm−3 calcium chloride solution

C 30 cm3 of 3.30 × 10−2 mol dm−3 hydrochloric acid

D 40 cm3 of 2.50 × 10−2 mol dm−3 sodium chloride solution

(Total 1 mark)

Q7.What is the total volume of gas remaining after 20 cm3 ethane are burned completely in 100 cm3 oxygen? All volumes are measured at the same pressure and the same temperature, which is above 100 °C.

C2H6 + 3 O2 2CO2 + 3H2O

A 40 cm3

B 100 cm3

C 120 cm3

D 130 cm3

(Total 1 mark)

Q8.A sample of hydrated nickel sulfate (NiSO4.xH2O) with a mass of 2.287 g was heated to remove all water of crystallisation. The solid remaining had a mass of 1.344 g.

(a) Calculate the value of the integer x. Show your working.

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(b) Suggest how a student doing this experiment could check that all the water had been removed.

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(Total 6 marks)

Q9.This question is about reactions of calcium compounds.

(a) A pure solid is thought to be calcium hydroxide. The solid can be identified from its relative formula mass.

The relative formula mass can be determined experimentally by reacting a measured mass of the pure solid with an excess of hydrochloric acid. The equation for this reaction is

Ca(OH)2 + 2HCl CaCl2 + 2H2O

The unreacted acid can then be determined by titration with a standard sodium hydroxide solution.

You are provided with 50.0 cm3 of 0.200 mol dm−3 hydrochloric acid. Outline, giving brief practical details, how you would conduct an experiment to calculate accurately the relative formula mass of the solid using this method.

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(b) A 3.56 g sample of calcium chloride was dissolved in water and reacted with an excess of sulfuric acid to form a precipitate of calcium sulfate.

The percentage yield of calcium sulfate was 83.4%.

Calculate the mass of calcium sulfate formed. Give your answer to an appropriate number of significant figures.

Mass of calcium sulfate formed = ......................... g (3)

(Total 11 marks)

Q10.This question is about a white solid, MHCO3, that dissolves in water and reacts with hydrochloric acid to give a salt.

MHCO3 + HCl → MCl + H2O + CO2

A student was asked to design an experiment to determine a value for the Mr of MHCO3. The student dissolved 1464 mg of MHCO3 in water and made the solution up to 250 cm3. 25.0 cm3 samples of the solution were titrated with 0.102 mol dm−3 hydrochloric acid. The results are shown in the table.

Rough 1 2 3

Initial burette reading / cm3 0.00 10.00 19.50 29.25

Final burette reading / cm3 10.00 19.50 29.25 38.90

Titre / cm3 10.00 9.50 9.75 9.65

(a) Calculate the mean titre and use this to determine the amount, in moles, of HCl that reacted with 25.0 cm3 of the MHCO3 solution.

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(b) Calculate the amount, in moles, of MHCO3 in 250 cm3 of the solution. Then calculate the experimental value for the Mr of MHCO3. Give your answer to the appropriate number of significant figures.

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(c) The student identified use of the burette as the largest source of uncertainty in the experiment.

Using the same apparatus, suggest how the procedure could be improved to reduce the percentage uncertainty in using the burette.

Justify your suggested improvement.

Suggestion ..........................................................................................................

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Justification .........................................................................................................

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(d) Another student is required to make up 250 cm3 of an aqueous solution that contains a known mass of MHCO3. The student is provided with a sample bottle containing the MHCO3.

Describe the method, including apparatus and practical details, that the student should use to prepare the solution.

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(Total 14 marks)

Q11.Which species contains an element with an oxidation state of +4?

A NO2+

B ClO3−

C H2SO3

D PCl5

(Total 1 mark)

Q12.The Mr of hydrated copper sulfate (CuSO4.5H2O) is 249.6.

Which of the following is the mass of hydrated copper sulfate required to make 50.0 cm3 of a 0.400 mol dm−3 solution?

A 3.19 g

B 3.55 g

C 3.71 g

D 4.99 g

(Total 1 mark)

Q13.Hydrogen is produced by the reaction of methane with steam. The reaction mixture reaches a state of dynamic equilibrium.

CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g) ∆H = +206 kJ mol−1

Which of the following shows how the equilibrium yield of hydrogen is affected by the changes shown?

Change Effect on

equilibrium yield of H2(g)

A Increase pressure decrease

B Add a catalyst increase

C Increase temperature increase

D Remove CO(g) as formed increase

(Total 1 mark)