Chemistry – Year 11 – Track 2 – 2018 Page 1 of 12

DEPARTMENT FOR CURRICULUM,

RESEARCH, INNOVATION AND LIFELONG LEARNING

Directorate for Learning and Assessment Programmes

Educational Assessment Unit

Annual Examinations for Secondary Schools 2018

YEAR 11 CHEMISTRY TIME: 2 hours

Name: _____________________________________ Class: ____________________

Useful Data Atomic numbers and relative atomic masses are shown in the periodic table printed below. One

mole of any gas occupies 22.4 dm3 at standard temperature (0 °C / 273 K) and pressure (1 atm. /

760 mmHg / 101.3 kPa).

Faraday constant = 96500 C mol-1 Q = I t

PERIODIC TABLE

Marks Grid [For Examiner’s use only]

Question

No.

Section A Section B

1 2 3 4 5 6 7 8

Max

Mark 10 10 10 10 20 20 20 20

Theory

Total

Actual

Mark

Theory Paper: 85% Practical: 15% Final Score: 100%

Track 2

Page 2 of 12 Chemistry – Year 11 – Track 2 – 2018

Section A: Answer ALL questions in the spaces provided.

This section carries 60 marks.

a) For each of the following mixtures, name ONE separation technique that should

be used to separate their components and state why this technique was chosen.

i) Ethanol and water

_______________________________________________________________

_______________________________________________________________

____________________________________________________________ [2]

ii) Iron filings and sodium chloride

_______________________________________________________________

_______________________________________________________________

____________________________________________________________ [2]

iii) Calcium carbonate and water

_______________________________________________________________

_______________________________________________________________

____________________________________________________________ [2]

b) The graph below shows the solubility curve for potassium nitrate.

1)

Chemistry – Year 11 – Track 2 – 2018 Page 3 of 12

i) How much potassium nitrate can dissolve in 100 g of water at 25 °C?

__________________________________________________________ [1]

ii) How much potassium nitrate can dissolve in 100 g of water at 90 °C?

___________________________________________________________ [1]

iii) Calculate the additional amount of potassium nitrate that would be needed so

that the solution would still be saturated when the temperature of the solution

at 25 °C increases to 90 °C.

______________________________________________________________

___________________________________________________________ [1]

iv) What would you see as the hot solution cools from 90°C to 25 °C?

______________________________________________________________

___________________________________________________________ [1]

Total: 10 marks

2) Lithium reacts with fluorine to form lithium fluoride.

a) Draw, showing all electron shells, dot cross diagrams of:

i) a lithium atom [2]

ii) a fluorine molecule [2]

iii) lithium fluoride [4]

Page 4 of 12 Chemistry – Year 11 – Track 2 – 2018

b) What kind of bonding is there in:

i) fluorine?

_________________________________________________________ [1]

ii) lithium fluoride?

_________________________________________________________ [1]

Total: 10 marks

3) Boron has two isotopes, boron-10 and boron-11. They exist naturally in the ratio of

2 is to 8.

a) State the group and period in which boron is found in the periodic table.

i) Group:

___________________________________________________________ [1]

ii) Period:

___________________________________________________________ [1]

b) What is the atomic number of boron?

____________________________________________________________ [1]

c) How many neutrons does boron-11 have?

_____________________________________________________________ [1]

d) What is the formula of boron trichloride?

_____________________________________________________________ [1]

e) Calculate the relative atomic mass of boron.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

_____________________________________________________________ [3]

f) Relative atomic mass of an element takes in consideration the relative abundance

of the __________________ and their atomic mass, compared with 1

12 the mass

of the carbon-_________________ isotope. [2]

Total: 10 marks

Chemistry – Year 11 – Track 2 – 2018 Page 5 of 12

4) Give the material present in each of the following situations by taking note of the

observations and descriptions of tests done:

a) Substance A is thermally stable. When heated on a blue Bunsen flame, it gives a

golden yellow flame. It reacts with acids to produce a gas that turns lime water

milky. Substance A is:

_____________________________________________________________ [2]

b) Substance B decomposes on heating to produce a gaseous mixture which has a

brown colour and relights a glowing splint. Heating substance B with sodium

hydroxide solution and then adding aluminium powder produces ammonia gas.

When drops of sodium hydroxide solution were added to a solution of substance B

a white precipitate was formed. This precipitate was insoluble in excess sodium

hydroxide solution. Heating substance B on a blue Bunsen flame gave no colour.

i) Substance B is ______________________________________________ [2]

ii) Write a balanced chemical equation, including state symbols, for the

decomposition of substance B.

__________________________________________________________ [3]

c) Look at the reaction scheme below. Name the unknown substances.

i) Substance C is ______________________________________________ [1]

ii) Substance D is ______________________________________________ [1]

iii) Substance E is ______________________________________________ [1]

Total: 10 marks

Page 6 of 12 Chemistry – Year 11 – Track 2 – 2018

5) The concentration of a sodium hydroxide solution is unknown. A lab technician needs

to find its concentration. The technician titrates this solution against a sulfuric acid

solution whose concentration is 0.1 mol dm-3.

a) The following diagram shows some of the equipment the technician uses. Label

the diagram in the spaces provided: [4]

b) Write a balanced chemical equation, including state symbols, for the reaction

between sodium hydroxide and sulfuric acid.

_____________________________________________________________ [3]

c) The technician needs to measure 25cm3 of the sodium hydroxide precisely. Name

the equipment that must be used to perform this task.

_____________________________________________________________ [1]

d) In which part of the equipment must the technician pour the sodium hydroxide

solution?

_____________________________________________________________ [1]

e) Since both sulfuric acid and sodium hydroxide are clear solutions, an indicator

must be used to show when neutralisation happens. Give the name of a suitable

indicator.

______________________________________________________________ [1]

Chemistry – Year 11 – Track 2 – 2018 Page 7 of 12

f) During titration, the technician collected information on how much acid was

needed to neutralise the alkali. The data collected is shown in the table below.

First Second Third Fourth

Titre / cm3 13.10 12.30 12.30 12.20

Calculate the average titre. Give your answer to two decimal places.

________________________________________________________________

______________________________________________________________ [2]

g) While taking readings for acid used, the technician needs to be very careful to read

the volume precisely. Name two precautions the technician must consider.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

______________________________________________________________ [2]

h) Calculate the amount of sulfuric acid in moles that reacted with sodium hydroxide.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

______________________________________________________________ [2]

i) Calculate the amount of sodium hydroxide in moles present in 25 cm3.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

______________________________________________________________ [2]

j) Calculate the concentration of sodium hydroxide.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

______________________________________________________________ [2]

Total: 20 marks

Page 8 of 12 Chemistry – Year 11 – Track 2 – 2018

Section B: Answer TWO questions only in the spaces provided.

This section carries 40 marks.

6) Copper is a very important elemental substance. It is found naturally in a variety of

ores. The name of one of these ores is malachite. It has the formula CuCO3.Cu(OH)2.

It is made of two minerals, CuCO3 and Cu(OH)2.

a) What is the full name of Cu(OH)2?

_____________________________________________________________ [1]

b) Give the substances that are produced when Cu(OH)2 is heated strongly? [2]

Substance 1: _____________________; Substance 2: _____________________

c) Complete and balance the chemical equation below. Include state symbols. [3]

Cu(OH)2(s) → ________________ + _________________

d) Both minerals produce a black powder after heating. When this black powder is

heated with carbon, a chemical reaction happens that produces copper metal.

CuO(s) + C(s) → Cu(s) + CO(g)

i) What is the name of this kind of reaction?

__________________________________________________________ [1]

ii) Which material is being reduced?

__________________________________________________________ [1]

iii) What is the oxidation state of copper metal?

__________________________________________________________ [1]

iv) What is the ratio of reacting particles of carbon and copper?

__________________________________________________________ [1]

v) Calculate the amount of carbon needed to produce 2 g of copper.

______________________________________________________________

______________________________________________________________

__________________________________________________________ [2]

vi) What happens if hot copper is exposed to air?

__________________________________________________________ [1]

e) Copper produced by reduction with carbon is not pure. It needs to be purified so

that it can be used for electrical wiring. The purification of copper is achieved using

electrolysis.

i) Should the impure copper be placed at the cathode or at the anode in the

electrolytic cell?

__________________________________________________________ [1]

Chemistry – Year 11 – Track 2 – 2018 Page 9 of 12

ii) Name a solution that can be used as the electrolyte for the purification of

copper.

__________________________________________________________ [1]

iii) Balance the half equation for what happens at the cathode. [2]

Cu2+(aq) + ______ → ______

iv) Calculate how much charge, in coulombs, is needed to discharge 1 mole of

copper? [Hint: 1 mole of electrons is equivalent to 96500C]

______________________________________________________________

__________________________________________________________ [1]

v) Calculate the amount of charge, in coulombs, that is needed to produce 2 g of

copper.

______________________________________________________________

__________________________________________________________ [2]

Total: 20 marks

7) The Haber process is an industrial reaction that produces ammonia on a large scale.

Nitrogen is reacted with hydrogen to produce ammonia.

nitrogen + hydrogen ⇌ ammonia

a) Write a balanced chemical equation for this reaction. Include state symbols.

_____________________________________________________________ [3]

b) What does the symbol ⇌ mean?

_____________________________________________________________ [1]

c) State the values of the three conditions that are necessary to produce the highest

amount of ammonia in the shortest period.

Temperature: _____________________________________________________

Pressure: ________________________________________________________

Catalyst: _____________________________________________________ [3]

d) State how the following changes would affect the equilibrium position and the

amount of ammonia produced:

i) decreasing pressure

______________________________________________________________

______________________________________________________________

__________________________________________________________ [2]

Page 10 of 12 Chemistry – Year 11 – Track 2 – 2018

ii) removing ammonia from the system

______________________________________________________________

______________________________________________________________

__________________________________________________________ [2]

iii) using a catalyst with a smaller surface area

______________________________________________________________

______________________________________________________________

__________________________________________________________ [2]

e) Name two uses of ammonia.

________________________________________________________________

_____________________________________________________________ [2]

f) Hydrogen is stored at room temperature in a gas cylinder. The gas cylinder has a

volume of 3 dm3 and a pressure of 7000 kPa at 293K.

i) Calculate the pressure this container experiences if its temperature decreases

to 273 K. Assume that the volume of the container stays the same.

Use the equation: 𝐏𝟏

𝐓𝟏 =

𝐏𝟐

𝐓𝟐

______________________________________________________________

__________________________________________________________ [2]

ii) Calculate the volume that the compressed hydrogen would occupy if it were to

be released into the air at s.t.p.

Use the equation: P1V1 = P2V2

______________________________________________________________

__________________________________________________________ [2]

iii) Find the number of moles of hydrogen stored in this container.

______________________________________________________________

______________________________________________________________

__________________________________________________________ [1]

Total: 20 marks

Chemistry – Year 11 – Track 2 – 2018 Page 11 of 12

8) Alkanes, alkenes and alkynes are all hydrocarbons. Ethane, ethene and ethyne are

three such compounds:

a) Ethane exists as a colourless gas at room temperature.

i) Give the general formula of alkanes. [1]

______________________________________________________________

ii) Draw the structure of a molecule of ethane. [2]

iii) Ethane and ethyne burn with different flames. Describe the flame seen in each

case and give a suitable explanation. [4]

Ethane:

______________________________________________________________

______________________________________________________________

Ethyne:

______________________________________________________________

______________________________________________________________

iv) Bromine water can be used to distinguish between alkanes and alkenes. State

what would be seen in both cases. [2]

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

b) Ethene is an unsaturated hydrocarbon. It is made by the cracking of long chain

hydrocarbon molecules such as C16H34.

i) What is meant by 'unsaturated'? [1]

______________________________________________________________

ii) Complete the following equation which illustrates the cracking of C16H34 to make

ethene and another hydrocarbon as the only products. [1]

C16H34 → C2H4 + _________

Page 12 of 12 Chemistry – Year 11 – Track 2 – 2018

iii) Fill in the blanks. [3]

Alkanes react by substitution reactions while alkenes react by ___________

reactions. This makes it possible for alkenes to form polymers. Two examples

of such polymers are _______________ and _____________.

iv) Calculate the volume of carbon dioxide, measured at s.t.p., produced by the

complete combustion of 1.40g of ethene. The chemical equation is given

below. [2]

C2H4 + 3O2 → 2CO2 + 2H2O

______________________________________________________________

______________________________________________________________

______________________________________________________________

______________________________________________________________

c) Ethyne can be made by the reaction of calcium carbide with water. Calcium

carbide, CaC2, is a greyish-white solid. Calcium hydroxide is the other product of

the reaction.

i) Balance the equation, and include state symbols, for the reaction between

calcium carbide and water. [2]

__CaC2(_) + __H2O(_) → __Ca(OH)2(_) + __C2H2(_)

ii) The mixture obtained was tested using universal indicator. Underline the

colour you would expect to obtain and explain your answer: [2]

Light red

Dark green

Dark blue

Explanation:

______________________________________________________________

______________________________________________________________

Total: 20 marks

End of paper