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Exampro GCSE Science ALimestone Test

Foundation Tier

Name:

Class:

Author: Mrs Bradford

Date: 18th September 2015

Time: 35

Marks: 37

Comments:

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Q1. In a quarry, limestone is blasted into pieces by explosives.The pieces of limestone are taken from the quarry by lorries.

(a) Draw a ring around the correct word in the box to complete the sentence.

building

Limestone can be used as a plastic material.

smart

(1)

(b) Tick ( ) one possible advantage for people who live near to the limestone quarry.

Advantage Tick ( )

causes more traffic

provides jobs

attracts tourists to the area

(1)

(c) Give two types of pollution that would be caused by the limestone quarry.

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

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

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(d) Limestone contains calcium carbonate (CaCO3).

Complete the two empty boxes in the table about the formula of calcium carbonate.

Name of element Symbol for the element Number of atoms in the formula

calcium Ca 1

carbon C 1

oxygen ................. .................

(2)

(e) Lorries take some of the limestone to be heated in a lime-kiln.Calcium carbonate, in the limestone, decomposes when heated.

Use the balanced chemical equation to help you complete the word equation for the decomposition of calcium carbonate.

CaCO3 → CaO + CO2

calcium carbonate → ....................................................... + carbon dioxide(1)

(Total 7 marks)

Q2. Limestone is mainly calcium carbonate, CaCO3

(a) Complete the two empty boxes in the table.

Symbol Element Number of atoms in the formulaCaCO3

Ca calcium 1

C carbon .................

O oxygen .................

(2)

(b) The diagram shows a lime kiln.A lime kiln is used to heat limestone to make quicklime.

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Use the diagram to help you to answer these questions.

(i) Draw a line from each substance to the name of the main chemical(s) that the substance contains.

Substance Name of the main chemical(s)

calcium carbonate

air

calcium oxide

quicklime methane

nitrogen and carbon dioxide

waste gases

nitrogen and oxygen

(3)

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(ii) A mixture of methane and air is used in the lime kiln.

Explain why.

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

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

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

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

(c) Tick ( ) two uses of limestone.

Use of limestone Tick ( )

as a building material

to make poly(ethene)

as a fuel

to make cement

(2)(Total 9 marks)

Q3. Carbon dioxide is produced when metal carbonates are heated.

(a) (i) Draw a ring around the correct answer to complete the word equation.

(1)

(ii) Draw a ring around the correct answer to complete the sentence.

combustion.

The reaction to produce carbon dioxide from magnesium carbonate is decomposition.

fermentation.

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(1)

(b) A student investigated what happens when metal carbonates are heated.

The student:

• used the apparatus to investigate heating four metal carbonates

• started the stop clock at the same time as he began to heat the metal carbonate

• stopped the stop clock when carbon dioxide was produced.

The student’s results are shown in the table.

Metal carbonate Time taken for the production of carbondioxide to start in seconds

Calcium carbonate 163

Copper carbonate 24

Magnesium carbonate 92

Zinc carbonate 67

(i) Tick ( ) the type of graph the student should draw from these results.

Type of graph Tick ( )

Bar chart

Line graph

Scatter graph

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(1)

(ii) Use the Chemistry Data Sheet to help you to answer this question.

Draw a ring around the correct answer to complete the sentence.

less

The more reactive the metal in the carbonate the

more time is taken for the

same

production of carbon dioxide to start.(1)

(iii) How did the student know that carbon dioxide was produced?

Use the diagram of the apparatus to help you to answer this question.

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

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

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

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

(Total 6 marks)

Q4. Limestone contains calcium carbonate.

(a) Calcium carbonate has the formula CaCO3.

Complete the sentence by writing in the correct numbers.

The formula of calcium carbonate is made up of 1 calcium atom, ............ carbon atom(s)

and ............ oxygen atom(s).(2)

(b) When limestone is heated it forms two other compounds.

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(i) State one safety precaution that you should take when heating limestone.

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

(ii) Name the white solid produced.

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

(iii) Why does a piece of limestone lose mass as it is heated?

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

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

(d) A company wants to quarry limestone. There are some houses near the quarry.

Residents in the houses say that they do not want a quarry next to them.

(i) Suggest two reasons why they do not want the quarry next to them.

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

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

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

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

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(2)

(ii) Suggest one possible benefit to the residents of having a quarry near their houses.

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

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

(Total 8 marks)

Q5. In the UK, railway sleepers are often made from concrete.

A scientist was asked to find the best concrete mixture to use so that railway sleepers would not break easily.

The scientist made:

• a mould to make small models of concrete sleepers

• concrete mixtures using crushed rock, sand, cement and water

• the equipment shown to add 0.1 kg masses until the model sleeper broke.

The scientist’s results are shown in the table.

Concrete mixturein % by volume

Total mass added to break the model sleeperin kg

Cement Sand Crushedrock Test 1 Test 2 Test 3 Mean

10 70 20 1.1 1.3 1.2 1.2

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20 60 20 2.6 2.5 2.4

30 50 20 3.3 3.3 3.3 3.3

40 40 20 3.8 4.0 3.3 3.9

50 30 20 4.5 4.2 4.3 4.3

(a) (i) Calculate the mean total mass added to break the model sleeper that has 20% cement by volume.

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

Mean = ........................... kg(1)

(ii) Choose one result in the table that the scientist should check and test again.

Result: % cement by volume ....................... Test number .......................

Explain why you chose this result.

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

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

(iii) What is the relationship between the total mass to break the model sleeper and the percentage (%) of cement by volume in the concrete mixture?

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

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

(iv) Suggest one other variable that the scientist should have recorded in the table of results.

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

(b) The scientist thought that full-size railway sleepers should be made from 30% cement, 50% sand and 20% crushed rock.

What other information about these three materials is needed before the scientist recommends using this mixture to make a full-size railway sleeper?

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

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

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

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

(Total 7 marks)

Exampro GCSE Science ALimestone Test

Higher Tier

Name:

Class:

Author: Mrs Bradford

Date: 14th September 2015

Time: 35

Marks: 33

Comments:

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Q1.Limestone is used for statues and buildings.

Limestone contains calcium carbonate (CaCO3).

(a) Figure 1 shows a limestone quarry.

Figure 1

© Henryk Sadura/iStock/Thinkstock

(i) Suggest one problem quarrying limestone will cause for people living nearby.

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

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

(ii) Suggest one benefit of quarrying limestone for people living nearby.

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

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

(iii) Why are limestone statues and buildings damaged by rain?

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

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

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(b) A student investigated what happens when limestone is heated, as shown in Figure 2.

Figure 2

This is the method the student used:

• measure the mass of limestone before heating

• measure the mass of solid product after heating

• repeat the experiment two more times.

The student’s results are shown in the table below.

Experiment 1 Experiment 2 Experiment 3

Mass of limestone before heating in g 5.0 5.0 5.0

Mass of solid product after heating in g 3.6 3.4 3.8

Mass lost in g 1.4 1.6

(i) Calculate the mass lost in experiment 3.

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

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

Mass lost = .............................. g(1)

(ii) Calculate the mean mass lost in the three experiments.

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

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

Mean mass lost = .............................. g(1)

(iii) Suggest one reason why the mass lost was not the same for the three experiments.

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

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

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(1)

(c) The word equation for the reaction when calcium carbonate is heated is:

calcium carbonate calcium oxide + carbon dioxide

(i) Complete the sentence.

The reaction when calcium carbonate is heated is called

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

(ii) Heating 5.0 g of calcium carbonate produces 2.8 g of calcium oxide.

Calculate the mass of carbon dioxide produced.

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

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

Mass of carbon dioxide = .............................. g(1)

(iii) Describe how to test a gas to show that it is carbon dioxide.

Test .......................................................................................................

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

Result ...................................................................................................

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

(Total 10 marks)

Q2. Limestone contains calcium carbonate (CaCO3).

(a) Name the type of reaction that takes place when calcium carbonate is heated strongly.

Name the products formed.

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

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

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

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

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

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

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(b) A student investigated what happens when limestone is heated strongly.

This is the method the student used:

• measure the mass of limestone before heating

• measure the mass of solid product after heating

• repeat the experiment three more times.

The student’s results are shown in the table below.

Experiment

1

Experiment

2

Experiment

3

Experiment

4

Mass of limestone before heating in g 5.0 5.0 5.0 5.0

Mass of solid product after heating in g

3.2 4.0 3.1 3.3

Mass lost in g 1.8 1.0 1.9 1.7

(i) Calculate the mean mass lost, taking account of any anomalies.

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

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

Mean mass lost = ................................. g(2)

(ii) The student used the chemical equation to calculate the maximum mass lost by 5.0 g of calcium carbonate when heated.

The maximum mass lost is 2.2 g.

Suggest and explain two reasons why the mean mass lost in the experiments to heat limestone is less than 2.2 g.

Do not include any reference to weighing errors in your answer.

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

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

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

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

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

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

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

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

(Total 9 marks)

Q3. (a) Limestone is a hard rock that is used as a building material.Limestone was used by the Egyptians to make plaster.

Reaction 1 – calcium carbonate, CaCO3, was decomposed by heating limestone

CaCO3 → CaO + CO2

Reaction 2 – water was added to the solid produced to make slaked lime

CaO + H2O → Ca(OH)2

Reaction 3 – a mixture of slaked lime and water was used as plaster. After the plaster had set it became even harder with age

Ca(OH)2 + CO2 → CaCO3 + H2O

(i) Name the solid formed when calcium carbonate decomposed.

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

(ii) Use the reactions to explain how the plaster became even harder with age.

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

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

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

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

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

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

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

(b) A gardener wanted to make a step up to his greenhouse door. He decided to use a mixture of cement and sand to make mortar.

He experimented using mixtures with different cement to sand ratios.

• The mortar mixtures were put in the same sized mould.

• Each mortar mixture was allowed to set hard.

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• He then dropped a metal ball from increasing heights until the set mortar cracked.

• He recorded his results in a table.

Volume of sandin cm3

Volume of cementin cm3

Height the metal ball dropped to crack the set mortar in cm

800 100 17

700 100 24

600 100 30

500 100 36

400 100 37

300 100 48

200 100 54

(i) What is the relationship between the volume of sand and the strength of the mortar?

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

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

(ii) The gardener was not sure about some of his results.

Use the results to explain why.

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

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

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

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

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

(Total 7 marks)

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Q4. Limestone contains calcium carbonate, CaCO3

(a) The flow chart shows the stages in the limestone cycle.

Write the name of the correct calcium compound in each empty box to complete the flow chart.

(3)

(b) Limestone is heated with clay to make cement.Cement is mixed with sand to make mortar.

A student investigated the strength of six mortar mixtures. Each mortar mixture contained 100cm3 cement but each contained a different volume of sand.

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To do the investigation the student:

• added and stirred water into each mortar mixture

• put each mixture into the same sized moulds

• left each mixture to set hard

• dropped a metal ball from increasing heights until the mortar cracked

• recorded the results in a table.

Volume of sand in cm3 Volume of cement in cm3

Height the metal ball was dropped from to crack the

mortar in cm

700 100 24

600 100 30

500 100 36

400 100 37

300 100 48

200 100 54

(i) What happens to the strength of the mortar as the volume of sand increases?

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

(ii) The student was worried about an anomalous result.

Which result was anomalous?

Volume of sand = ................. cm3

Explain why you have chosen this result.

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

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

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

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

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(c) The student repeated the investigation but used six concrete mixtures.

From the results the student concluded correctly that concrete was stronger than mortar.

Suggest one reason why concrete is stronger than mortar.

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

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

(Total 7 marks)

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M1.(a) (i) any one from:

• destruction of habitats• fewer plants / trees to absorb carbon dioxide• dust / noise / air / visual (pollution)

allow breathing problems• more traffic

1

(ii) any one from:

• provides employment• local business make more profit• new transport links

ignore future use of quarry1

(iii) (rain water is) acidic1

(b) (i) 1.2(g)1

(ii) 1.4(g)allow ecf from (b)(i)

1

(iii) any one from:

• temperature of the flame variedallow flame was too hot or not hot enough

• different purity of the limestone• incorrect measurement of mass• heated for different times

1

(c) (i) decomposition1

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(ii) 2.2(g)1

(iii) limewatertest must be correct to gain second mark

1

turns cloudyallow turns milky or white (precipitate)

1[10]

M2. (a) causes dust pollution1

increases traffic1

(b) (i) decomposition1

(ii) 44(g)1

(c) (calcium) hydroxide1

(calcium) carbonate1

substances must be in the order shown[6]

M3. (a) building1

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(b) provides jobs1

(c) any two from:ignore references to water

• noiseallow sound pollution

• dust / visual pollutionaccept global dimmingignore smoke

• air / atmospheric

• exhaust gasesaccept acid rain / global warming / named gaseous pollutants

• (more) trafficaccept more lorries

2

(d) Oignore any numbers

1

3 / three1

(e) calcium oxideaccept quicklimedo not accept calcium dioxide

1[7]

M4. (a) 1 / one1

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3 / three1

(b) (i) air linked to nitrogen and oxygen1

quicklime linked to calcium oxide1

waste gases linked to nitrogen and carbon dioxide1

(ii) mixture burns / combustsaccept methane reacts with air / oxygenaccept as a fuel

1

to provide energy / heat1

(c) as a building material1

to make cement1

[9]

M5.(a) (thermal) decompositionaccept limestone decomposesallow endothermic

1

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(to produce) calcium oxide / CaO or quicklime1

(to produce) carbon dioxide / CO2

accept a correct word or chemical equation for the last two marking points

1

(b) (i) 1.8(g)accept correct answer with or without workingaccept 1.8 + 1.9 + 1.7 ÷ 3 for 1 markif no other mark awarded allow 1 mark for 1.6(g)or any calculation with one error

2

(ii) the limestone was not pure (calcium carbonate) or contained impurities1

so less carbon dioxide was produced1

the temperature was not high enoughallow not heated for long enough

1

so the limestone / calcium carbonate did not fully decompose / react1

[9]

M6. (a) ߦ one / 1 (molecule of) methane (reacts with) two / 2 (molecules of) oxygen1

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• two / 2 (molecules of) water / steam / hydrogen oxide and one / 1 (molecule of) carbon dioxide (are produced)

if no other marks awarded all four names correctorcorrect number and name for two moleculesor4 correct numbers gains 1 markallow all four names correct and correct number of atoms in each substance for 2 marks

1

(b) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.

0 marks

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Level 1 (1-2 marks)There is a simple description of a positive and / or a negative impact caused by the plan to quarry limestone and / or make cement.

Level 2 (3-4 marks)There is a clear description of both a positive and a negative impact caused by the plan to quarry limestone and / or make cement.

Level 3 (5-6 marks)There is a detailed description of both positive impacts and negative impacts caused by the plan to quarry limestone and / or make cement.

examples of the chemistry points made in the response

Positive impacts:

• Limestone / cement is used for building

• Limestone needed for industrial processes

• Company landscapes / provides recreation facilities in the quarry after use

• Provides employment

• Improves local economy

• Improved transport links

Negative impacts:

• Destruction of habitats

• Fewer plants / trees to absorb carbon dioxide

• Example of visual pollution

• Example of noise pollution

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• Example of atmospheric pollution

• More traffic6

[8]

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E1.(a) (i) A majority of students achieved the mark, usually for stating that noise, dust or visual pollution would be a problem of quarrying limestone for people living nearby.

(ii) More than half of the students correctly suggested that either the availability of jobs or economic improvement would be a benefit for people living near the limestone quarry.

(iii) Less than half of the students realised that limestone statues and buildings are damaged because rain water is acidic. Several students incorrectly thought that it was because limestone is a soft rock.

(b) (i) Most students correctly calculated the mass lost when the limestone was heated in experiment 3.

(ii) A few students did not understand how to calculate a mean from the three values of the mass lost. Most managed to calculate the correct answer of 1.4 g or an allowed correct answer from their error carried forward from part (b)(i).

(iii) The question was poorly answered. Responses showed that there was a lack of understanding of what the question was asking. The most common mark seen for this question was zero. Any reference to incorrect measurement of mass was creditworthy. Although many students incorrectly suggested that the student had either used different masses of limestone or used the same piece of limestone for the three experiments. Of the students who gained credit, the most common correct answers were that the temperature was not the same or the limestone was not heated for different amounts of time. The idea of impurities in the limestone was rarely seen.

(c) (i) Most students knew that the reaction when calcium carbonate is heated is called thermal decomposition.

(ii) Most students correctly calculated that if heating 5.0 g calcium carbonate produced 2.8 g calcium oxide then the mass of carbon dioxide produced would be 2.2 g.

(iii) Many students did not attempt to answer this question. The most common mark for this question was zero. About a quarter of the students gained full marks for using limewater for the test and stating the result that carbon dioxide turns it cloudy. Several gave the correct result but gave an incorrect test so gained no credit. Many students described tests not for carbon dioxide but for hydrogen or oxygen or for unsaturation in hydrocarbons.

E3. (a) The majority of candidates knew that limestone could be used as a building material.

(b) The majority of candidates were able to identify that one possible advantage for the people who lived near to the limestone quarry was that it could provide jobs.

(c) Many candidates just stated environmental pollution or emissions without giving the type of environmental pollution or the type of emission. However, most candidates did score two marks here. The most popular correct answers were dust, noise and pollution caused

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by carbon dioxide in exhaust gases.

(d) Most candidates correctly gave O as the symbol for oxygen. The number of oxygen atoms in the formula CaCO3 was often stated incorrectly as being two.

(e) Most candidates correctly gave calcium oxide as the compound with the formula CaO. A few candidates thought incorrectly that the name of the compound was calcium oxygen.

E4. (a) A majority of students gained credit for understanding that in the formula of calcium carbonate there is one carbon atom and there are three oxygen atoms.

(b) (i) Students should use a ruler to draw lines between boxes. Several students incorrectly thought that the main chemicals in air were nitrogen and carbon dioxide instead of nitrogen and oxygen. Few students gained all three marks.

(ii) Surprisingly, very few of the students could explain that a mixture of methane and air burns releasing energy to heat the lime kiln. There were many incorrect ideas, such as, ‘act as a catalyst’, ‘blow out the waste gases’ and ‘react with the limestone to produce quicklime’.

(c) The majority of students knew that limestone is used as a building material and to make cement.

E5.(a) This question was well answered with a large proportion of students gaining 2 or 3 marks. The correct type of reaction, that is, thermal decomposition was seen in many answers; but other incorrect reactions, such as combustion, were often mentioned. Calcium oxide and carbon dioxide were correctly identified as the products by a large percentage of students. A number of weaker students were confused by the reaction and gave a wide variety of products, such as water, calcium, carbon and carbon monoxide. Many students incorrectly thought water was produced because the limestone was damp and carbon monoxide was produced due to incomplete combustion.

(b) (i) The responses for this question showed that most students understood how to handle anomalous values. There were fewer students this year who included all values in their calculation of the mean mass lost.

(ii) The question was poorly answered. Responses showed that there was a lack of understanding of what the question was asking. Many students tried to explain the difference between the values obtained by each of the four experiments, without any reference to the calculated, theoretical value. Although the question stated that weighing errors should not be included a large proportion of students still mentioned

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these in their responses. Any reference to human or experimental errors was ignored. The most common mark seen for this question was zero, while a very small proportion of students gained the higher marks. Of the students who gained credit, the most common answers seen mentioned that the temperature was not high enough or the limestone was not heated for long enough or that the limestone did not fully decompose. The idea of impurities in the limestone was seen less often. Although most students clearly understood that carbon dioxide was produced, the reduced decomposition was rarely related to production of less carbon dioxide.

E6. (a) There were only a small number of correct answers. This indicates that the number of reacting molecules or the number of atoms involved in symbol equations is not well understood. Many students could correctly name three of the chemicals. The main difficulty experienced was that very few students knew that CH4 is methane. It was surprising that H2O, the formula for water, was not always known.

(b) This was the first of the new six mark questions including quality of written communication. This was marked holistically, the answer linked to three levels on a best fit basis. The number of positive impacts and negative impacts was taken into account, as was the detail given in each one. A good answer would cover both the positive impacts and negative impacts of quarrying limestone and making cement. The answer should be written as continuous prose. Bullet points are acceptable, however, each point should be written as a complete sentence. No credit is given for simply repeating things that are given in the stem to the question. The spelling, punctuation and grammar, together with the use of specialist terms, are also considered before a final mark is awarded. Most students were able to give at least one positive impact and one negative impact of quarrying in this area. However, although descriptions were often clear, many lacked the necessary detail to achieve marks at the highest level. Vague comments, such as ‘this is bad for the environment’ or ‘this causes a lot of pollution’ are not creditworthy. Where reference is made to visual, noise or atmospheric pollution, students must clearly describe the source of this pollution to gain any credit. Not surprisingly, few students scored full marks, but equally very few failed to score.

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