queen elizabeth school some revision questions … elizabeth school page 1 some revision questions...

Queen Elizabeth School

Some Revision questions based on year 9 work (foundation)

Q1.A student investigated the rate of reaction between marble chips and hydrochloric acid.

Figure 1 shows the apparatus the student used.

(a) What is A?

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.

(3)

(c) Use Figure 2 to complete 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.

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(e) Another student investigated the rate of a different reaction. Table 3 shows the results from the different reaction.

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.

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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.

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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)


Q2.A student investigated the rate of reaction between sodium thiosulfate and dilute hydrochloric acid.

The student placed a conical flask over a cross on a piece of paper.

The student mixed the solutions in the flask.

The solution slowly went cloudy. The student timed how long it took until the cross could not be seen.

The equation for the reaction is:

Na2S2O3(aq) + 2 HCl(aq) → 2 NaCl(aq) + H2O(l) + SO2(g) + S(s)

sodium

thiosulfate +

hydrochloric acid

→ sodium chloride

+ water + sulfur

dioxide + sulfur

(a) Explain why the solution goes cloudy.

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

(b) The student repeated the experiment with different concentrations of sodium thiosulfate.

Concentration of

sodium thiosulfate in moles per dm3

Time taken until the cross could not be seen in seconds

Trial 1 Trial 2 Trial 3 Mean

0.040 71 67 69 69

0.060 42 45 45 44

0.080 31 41 33


(i) Calculate the mean time for 0.080 moles per dm3 of sodium thiosulfate.

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Mean = ........................................ seconds (2)

(ii) Describe and explain, in terms of particles and collisions, the effect that increasing the concentration of sodium thiosulfate has on the rate of the reaction.

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............................................................................................................... (3) (Total 7 marks)

Q3.The Sun produces helium atoms from hydrogen atoms by nuclear fusion reactions.

Hydrogen Helium

(a) Describe the differences in the atomic structures of a hydrogen atom and a helium atom.

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(b) The Sun consists of 73% hydrogen and 25% helium. The rest is other elements. One of the other elements in the Sun is neon.

Use the Chemistry Data Sheet to help you to answer these questions.

(i) Complete the diagram to show the electronic structure of a neon atom.

(1)

(ii) Why is neon in the same group of the periodic table as helium?

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............................................................................................................... (1)(Total 5 marks)

Q4.This question is about hydrocarbons.

(a) The names and formulae of three hydrocarbons in the same homologous series are:

Ethane C2H6

Propane C3H8

Butane C4H10

The next member in the series is pentane. What is the formula of pentane?

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

(b) Which homologous series contains ethane, propane and butane?

Tick one box.

Alcohols

Alkanes

Alkenes

Carboxylic acids

(1)


(c) Propane (C3H8) is used as a fuel.

Complete the equation for the complete combustion of propane.

C3H8 + 5O2 → 3 .............................. + 4 ................................. (2)

(d) Octane (C8H18) is a hydrocarbon found in petrol.

Explain why octane is a hydrocarbon.

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

(f) Pollutants cause environmental impacts.

Draw one line from each pollutant to the environmental impact caused by the pollutant.

Pollutant

Environmental impact caused

by the pollutant

Acid rain

Oxides of nitrogen

Flooding

Global

dimming

Particulate

matter

Global warming

Photosynthesis

(2)(Total 11 marks)


Q5.Plastic and glass can be used to make milk bottles.

The figure below shows the percentage of milk bottles made from glass between 1975 and 2010.

(a) Plot the points and draw a line on the figure above to show the percentage of milk bottles made from materials other than glass between 1975 and 2010.

(3)

(b) The table below gives information about milk bottles.

Glass milk bottle Plastic milk bottle

Raw materials Sand, limestone,

salt Crude oil

Bottle material Soda-lime glass HD poly(ethene)

Initial stage in production of bottle material

Limestone and salt used to produce

sodium carbonate.

Production of naphtha fraction.

Maximum temperature in production process

1600 °C 850 °C

Number of times bottle can be used for milk

25 1

Size(s) of bottle 0.5 dm3 0.5 dm3, 1 dm3, 2 dm3, 3

dm3

Percentage (%) of recycled material used in new bottles

50 % 10 %


Evaluate the production and use of bottles made from soda-lime glass and those made from HD poly(ethene).

Use the information given and your knowledge and understanding to justify your choice of material for milk bottles.

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............................................................................................................................. (6) (Total 9 marks)

Q6.This question is about oil reserves.

(a) Diesel is separated from crude oil by fractional distillation. Describe the steps involved in the fractional distillation of crude oil.

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(b) Diesel is a mixture of lots of different alkanes. What are alkanes?

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(c) Petroleum products, such as petrol, are produced from crude oil. The graph shows the possible future production of petroleum products from crude oil and the expected demand for petroleum products.

Canada’s oil sands hold about 20% of the world’s known crude oil reserves.

The oil sands contain between 10 to 15% of crude oil. This crude oil is mainly bitumen.

In Canada the oil sands are found in the ground underneath a very large area of forest. The trees are removed. Then large diggers and trucks remove 30 metres depth of soil and rock to reach the oil sands. The oil sands are quarried. Boiling water is mixed with the quarried oil sands to separate the bitumen from the sand. Methane (natural gas) is burned to heat the water.

The mixture can be separated because bitumen floats on water and the sand sinks to the bottom of the water. The bitumen is cracked and the products are separated by fractional distillation.

Use the information given and your knowledge and understanding to suggest the advantages and disadvantages of extracting petroleum products from oil sands.

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........................................................................................................................ (6)(Total 11 marks)

The answers

M1.(a) cotton wool 1

(b) all points correct ± ½ small square

2

allow 1 mark if 5 or 6 of the points are correct best fit line

must not deviate towards anomalous point 1

(c) (mass) 2.1 (g)

allow ecf from drawn best fit line 1

(time) 100 (s)

1

(d) a gas is produced 1

which escapes from the flask 1

(e) 1

0.07 (g / s) allow ecf answer correctly calculated to 2 decimal places

1

(f) collect the gas in a gas syringe 1

measured the volume of gas allow carbon dioxide for gas

1


allow for 1 mark collected gas or counted bubbles

(g) The particles have more energy 1

The particles move faster 1

[14]

M2.(a) because sulfur / S forms 1

which is insoluble / a solid / a precipitate 1

(b) (i) 32 correct answer with or without working gains 2 marks accept evidence of 31 + 33 / 2 for 1 mark allow 35 for 1 mark

2

(ii) reaction rate increases if incorrect reference to energy = max 2

1

because of more particles (per unit volume) allow because particles are closer together

1

and because there is an increase in frequency of collisions accept because particles are more likely to collide or higher chance of collision ignore more (successful) collisions

1[7]

M3.(a) hydrogen has one proton whereas helium has two protons accept numbers for words accept hydrogen only has one proton ignore references to groups

1

hydrogen has one electron whereas helium has two electrons accept hydrogen only has one electron allow helium has a full outer shell (of electrons)

1

hydrogen has no neutrons or helium has two neutrons if no other mark awarded, allow helium has more electrons / protons / neutrons for 1 mark

1

(b) (i) 2 electrons on first shell and 8 electrons on outer shell

1

(ii) they have a stable arrangement of electrons accept they have full outer energy level / shell of electrons do not accept they have the same number of electrons in their outer energy level / shell allow they are noble gasesignore they are in group 0

1[5]

M4.(a) C5H12

1

(b) Alkanes 1

(c) (3) CO2

(4) H2O 1

allow for 1 mark 4 CO2 + 3 H2O


(d) contains hydrogen and carbon 1

(hydrogen and carbon) only 1

(f)

2

[11]

M5.(a) all points correct ±1 small square allow 1 mark for 6 or 7 plots

2

Year Percentage (%) of bottles made from

other materials

1975 5

1980 10

1985 22

1990 42

1995 70

2000 72

2005 90

2010 95

1

(b) Level 3 (5–6 marks): A detailed and coherent argument is provided which considers a range of issues and comes to a conclusion consistent with the reasoning. Level 2 (3–4 marks): An attempt to describe the advantages and disadvantages of the production and uses is made, which comes to a conclusion. The logic may be inconsistent at times but builds towards a coherent argument. Level 1 (1–2 marks): Simple statements made. The logic may be unclear and the conclusion, if present, may not be consistent with the reasoning. 0 marks: No relevant content. Indicative content

• glass – 2 stages in production of soda-lime glass • glass – second stage, heating sand, limestone and sodium carbonate • HDPE – 3 stages in production • HDPE – second stage, cracking of naphtha to obtain ethene • HDPE – third stage, polymerisation of ethene • fewer stages in glass production, may be quicker


• higher temperature in glass manufacture, therefore maybe higher energy requirement

• glass bottle can be reused • consideration of collection / cleaning costs to reuse glass bottles • other glass products can be made from recycled glass • plastic has greater range of sizes • both produced from limited raw materials • higher percentage recycled materials in glass conserves raw materials

This indicative content is not exhaustive, other creditworthy responses should be awarded marks as appropriate.

6

[9]

M6.(a) heat to vaporise (the crude oil) do not accept cracking / burning

1

vapours condense 1

at different temperatures allow they have different boiling points

1

(b) (alkanes) are hydrocarbons or are compounds of hydrogen and carbon only 1

alkanes are saturated or have only (carbon-carbon) single bonds accept have no (carbon-carbon) double bonds accept general formula is CnH2n+2 for 2 marks

1

(c) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. 0 marksNo relevant content. Level 1 (1-2 marks)There is a basic description of at least one advantage or one disadvantage of extracting petroleum products from oil sands. Level 2 (3-4 marks)There is a clear description of an advantage and a disadvantage of extracting petroleum products from oil sands. Level 3 (5-6 marks)There is a detailed description of both advantages and disadvantages of extracting petroleum products from oil sands. Examples of the chemistry/environmental/economic/social points made in the response Advantages: • the oil sands are needed because crude oil is running out • this crude oil is needed because demand is increasing • the oil sands contain a large amount of crude oil • the oil sands could improve Canada’s economy • the oil sands provide employment for a lot of people • the trees / forest are used for wood products / fuel Disadvantages: • destruction of environment / habitats • fewer trees / forests to absorb carbon dioxide • specified pollution, for example, visual, noise, atmospheric (including dust),

water (including river or drinking) with cause, e.g. gases / particulates from burning diesel

• large amounts of methane (natural gas) are used to provide energy • energy / fuel needed for cracking and fractional distillation • burning fuel releases carbon dioxide • crude oil / natural gas contains locked up carbon • crude oil is non-renewable

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queen elizabeth school some revision questions … elizabeth school page 1 some revision questions...

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