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GCSE in SCIENCE A Specimen Assessment Materials 65

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GCSE SCIENCE A FOUNDATION TIER (Grades G-C) CHEMISTRY 1 – The Earth and its resources SPECIMEN PAPER (1 hour)

INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces at the top of this

page. Answer all questions. Write your answers in the spaces provided in this booklet. INFORMATION FOR CANDIDATES The number of marks is given in brackets at the end of each question or part-question. You are reminded that assessment will take into account the quality of written

communication used in your answer to question 10.


Answer all questions.

1. (a) The key below represents atoms of some elements.

(i) The gas methane has the formula CH4.

Choose the letter of the diagram below that represents a molecule of methane. [1]

Letter .................................. (ii) Use the key given above to draw diagrams representing the

molecules I hydrogen, H2, [1] II ammonia, NH3. [1]

(b) The chemical formula of carbonic acid is H2CO3. (i) State how many carbon atoms are present in the formula H2CO3. .................... [1] (ii) Give the total number of atoms shown in the formula. .................... [1]


2. (i) The box below shows the names of some gases found in the atmosphere.

argon carbon dioxide neon nitrogen oxygen Choose gases from the box above to answer parts I and II. Each gas can be used once, more than once, or not at all. Name the

I two gases kept in balance in the atmosphere by the two processes of respiration and photosynthesis,

................................................ and ................................................ [1]

II gas which most scientists believe is mainly responsible for global

warming. ................................................................................... [1]

(ii) In the 1960s, Alfred Wegener's idea that all the continents were once joined

together as one big land mass was accepted by other scientists.

earthquakes similar patterns of fossils

ocean currents shapes of continents

Choose from the box above two types of evidence that Wegener used to support his idea. [2]

1. ........................................................................... 2. ...........................................................................


3. The diagrams below show stages in making the compound copper sulfate by reacting copper carbonate with dilute sulfuric acid.

(i) State why copper carbonate is added in excess. [1] ............................................................................................................................ (ii)

boiling evaporating dissolving filtering Choose, from the box above, the name for the process occurring in: I Stage 2 ................................................................ [1] II Stage 3 ................................................................ [1] (iii) The reaction that takes place in stage 1 can be described by the following

word equation.

sulfuric copper copper carbon acid + carbonate sulfate + water + dioxide

I Choose, from the box below, the name of the group of compounds to

which copper sulfate belongs.

acid base salt

…………………………………………………….. [1] II All of the substances in the above equation are compounds. State

how compounds are different to elements. [1] ................................................................................................................ (iv) If sodium carbonate were used instead of copper carbonate, give the

chemical name of the crystals formed in the evaporating basin in stage 3. [1] ............................................................................................................................


4. Acid rain is an increasing environmental problem. One of the causes is the production of nitrogen oxides.

(i) The pie chart below shows the sources of the nitrogen oxides present in the

atmosphere.

Use the information in the chart to calculate the percentage of nitrogen oxides

present in the atmosphere due to road transport. [1] ............................................................................................................................ ............................................................................................................................ (ii) State two ways in which acid rain affects the environment. [2] ............................................................................................................................ ............................................................................................................................


(iii) The table below shows the amount of nitrogen oxides released into the atmosphere in the year shown.

Year 1970 1980 1990 2000

thousand tonnes 2501 2581 2759 1737

Since 1993, all new cars have been fitted with a catalytic converter. Catalytic converters remove nitrogen oxides from car exhaust gases by passing them over a platinum catalyst.

I Suggest why the amount of nitrogen oxides released into the

atmosphere increased between 1970 and 1990. .................................................................................................... [1] II Describe how the data in the table above can be used to support the

view that catalytic converters are effective. [2] ............................................................................................................................ ............................................................................................................................


5. A small piece of magnesium ribbon was placed into excess dilute hydrochloric acid in a boiling tube. The temperature of the reaction mixture was recorded using a temperature sensor and displayed on a computer screen.


(a) (i) Use the graph to answer parts I and II. I State the time taken for the reaction to come to an end. [1] .................... seconds II State the maximum temperature rise recorded during the reaction. [1] ........................................................................................................... (ii) Give one advantage of using a temperature sensor and computer to

record the temperature. [1] ............................................................................................................... ............................................................................................................... (b) (i) Other than the temperature change, give two observations which

suggest that a chemical change is occurring when magnesium is added to dilute acid. [2]

............................................................................................................... ............................................................................................................... (ii) The following table shows the colours of universal indicator at different

pH ranges.

Colour Red Orange Yellow Green Blue Navy Blue Purple

pH range 0-2 3-4 5-6 7 8-9 10-12 13-14

One of the products of the reaction is magnesium chloride.

Magnesium chloride solution is neutral. Give the colour of universal indicator in magnesium chloride solution. [1]

Colour ..................................


6. (i) State why a nano-sized particle of a given substance could be considered to be a different material and why it could therefore have different uses. [1]

............................................................................................................................ (ii) A newspaper reported that 'nano-sized particles could have negative effects

in the long-term on health and the environment'. Chemists are currently developing nano-scale materials for use in solar cells

which could provide a major development in our ability to provide electricity using the sun's energy.

Describe the potential benefits of this research and state whether or not, in

your opinion, those benefits outweigh the potential risk involved. [3] ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................


7. This question is about the reactivity of metals. (a) A teacher carried out the following two experiments in a fume cupboard. Experiment 1 A mixture of aluminium powder and iron oxide was heated strongly using the

equipment shown.

The reaction that took place can be summarised by the following word

equation.

aluminium + iron oxide → aluminium oxide + iron Experiment 2 The above experiment was then repeated using a mixture of iron powder and

copper oxide. The word equation for this reaction is shown below.

iron + copper oxide → iron oxide + copper (i) Use the results of the two reactions to place the three metals,

aluminium, copper and iron in order of decreasing reactivity. [2] Most reactive .......................................................... .......................................................... .......................................................... (ii) The teacher said that iron oxide, in Experiment 1, and copper oxide, in

Experiment 2, had both been reduced. State the meaning of the term reduced. [1] ................................................................................................................ ................................................................................................................ ................................................................................................................


(b) Zinc is more reactive than copper. Excess zinc powder was added to blue copper sulfate solution. During the reaction, the blue solution became colourless and a brown solid

was formed.

(i) Name the colourless solution A. [1] ................................................. (ii) Name the brown solid B. [1] .................................................


8. (a) The table below shows some physical properties of Group 1 elements.

Element Melting point / °C

Boiling point / °C

Density / gcm-3

Electrical conductivity

lithium 180 1340 0.50 good sodium 880 0.97 good

potassium 63 766 0.86 good rubidium 39 686 1.50 good caesium 29 669 1.90 good

Use only the information in the table to answer parts (i) and (ii).

(i) State the property of Group 1 metals which is common to all metals. [1]

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

(ii) Predict the approximate value for the melting point of sodium and give

a reason for your choice. [2]

Melting point .......................... °C

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

(b) Sodium reacts vigorously with fluorine to give sodium fluoride as shown in the following word equation. sodium + fluorine sodium fluoride

Balance the symbol equation shown below. [2]

Na + F2 NaF


(c) Sodium fluoride is added to the water supply in some areas because fluoride ions have been shown to cause a reduction in tooth decay.

Scientists established this link by carrying out large scale surveys. (i) Give a reason why scientists required large numbers of people to

complete their surveys in order to establish the link between fluoride ions and a reduction in tooth decay. [1]

................................................................................................................ ................................................................................................................ (ii) Suggest why it would be better for this type of survey to be carried out

by an independent consumer group rather than by a company which manufactures toothpaste. [1]

................................................................................................................ ................................................................................................................ (iii) Give one reason why many people are against the fluoridation of the

water supply. [1] ................................................................................................................ ................................................................................................................


9. John and Betsan wanted to investigate the link between the number of carbon atoms present in molecules of different fuels and the amount of heat they released on burning.

They were told that molecules of fuels A-E had the following numbers of carbon atoms.

Fuel Number of carbon atoms per molecule

A 1 B 2 C 3 D 4 E 5

They decided to use the apparatus below to make their measurements.

They recorded the initial temperature of the water and lit the burner. They placed the burner below the flask and heated the water for 1 minute. They then removed the burner and noted the highest temperature recorded on the thermometer.


(i) In addition to the heating time, name one of the variables that they should keep constant during each of their experiments in order to ensure that their results are valid. [1]

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

They collected the following results for fuels A-D but did not have a sample of fuel E to test.

Temperature of water (°C) Fuel Number of carbon atoms per

molecule Initial Final Increase

A 1 19 29 10 B 2 20 32 12 C 3 20 35 15 D 4 19 38 E 5

(ii) Calculate, and record in the table, the increase in temperature for fuel D. [1]

(iii) Plot a graph to show the relationship between the number of carbon atoms per molecule and the temperature increase when each fuel is burned for 1 minute. [3]

0 1 2 3 4 5

Number of carbon atoms

Temperature increase

/ ºC


(iv) Describe the general trend shown by your graph. [1] ............................................................................................................................

(v) Use your graph to predict the temperature increase which would be produced by burning fuel E for 1 minute. [1]

........................................ºC

(vi) Betsan told John they should try to find out whether or not the results are 'repeatable'. Describe how they should do so. [1]

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

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

(vii) State what you think is the most likely reason that the values they measured are not the true values. Suggest how the method used could be changed in order to improve the quality of the results. [2]

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

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


10. It has been suggested that waste plastics could be recycled and used to manufacture houses cheaply and quickly.

Evaluate this potential use of waste plastics. [6 QWC]

In your answer you should refer to • the properties of plastics • what happens to most plastics once they have been used • the need to make the best possible use of the Earth's natural resources

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FORMULAE FOR SOME COMMON IONS

POSITIVE IONS NEGATIVE IONS

NAME FORMULA NAME FORMULA

Aluminium Al3+ Bromide Br-

Ammonium NH4+ Carbonate CO3

2-

Barium Ba2+ Chloride CI-

Calcium Ca2+ Fluoride F-

Copper(II) Cu2+ Hydroxide OH-

Hydrogen H+ Iodide I-

Iron(II) Fe2+ Nitrate NO3-

Iron(III) Fe3+ Oxide O2-

Lithium Li+ Sulfate SO42-

Magnesium Mg2+

Nickel Ni2+

Potassium K+

Silver Ag+

Sodium Na+

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