Paper 2-style practice paper: Higher — question paper

Section A: Multiple-choice questions[10 marks]

Choose one answer for each question. Each question is worth 1 mark.

1. 1

   A tangent drawn at 30 s on a gas-volume graph rises 32 cm³ over 16 s. The rate at 30 s is

   1. A2.0 cm³/s
   2. B0.5 cm³/s
   3. C16 cm³/s
   4. D512 cm³/s
   ( )
2. 2

   Increasing the temperature of a reaction increases the rate because

   1. Athe activation energy increases
   2. Bparticles get larger
   3. Cmore particles exceed the activation energy and collide more often
   4. Dthe products become more stable
   ( )
3. 3

   Increasing the pressure on H₂(g) + I₂(g) ⇌ 2HI(g) shifts the equilibrium

   1. Aleft
   2. Bnowhere — equal gas moles on each side
   3. Cright
   4. Dtowards the catalyst
   ( )
4. 4

   The atom economy of a reaction with one desired product of Mr 80 and one waste product of Mr 20 is

   1. A80%
   2. B20%
   3. C75%
   4. D100%
   ( )
5. 5

   Which equation shows the polymerisation of chloroethene?

   1. AC₂H₃Cl + H₂O → polymer
   2. BnC₂H₄ → nCO₂
   3. CnC₂H₃Cl → (–C₂H₃Cl–)n
   4. DC₂H₃Cl + Cl₂ → C₂H₃Cl₃
   ( )
6. 6

   A white precipitate that dissolves in excess sodium hydroxide solution indicates

   1. AFe²⁺
   2. BCu²⁺
   3. CCa²⁺
   4. DAl³⁺
   ( )
7. 7

   Flame emission spectroscopy quantifies metal ions by

   1. Ameasuring light intensity against a calibration curve
   2. Bweighing the residue left after burning
   3. Ctiming how long the flame lasts
   4. Dmatching the flame to a colour chart
   ( )
8. 8

   Galvanising protects steel because zinc is

   1. Aunreactive
   2. Bmore reactive than iron and oxidises sacrificially
   3. Cwaterproof
   4. Dcheaper than paint
   ( )
9. 9

   The forward reaction of an equilibrium is exothermic. Lowering the temperature shifts the equilibrium

   1. Aleft
   2. Bin the endothermic direction
   3. Cright
   4. Dnot at all
   ( )
10. 10

    Condensation polymerisation differs from addition polymerisation because it

    1. Auses only alkene monomers
    2. Bneeds no functional groups
    3. Cnever makes useful materials
    4. Dreleases a small molecule such as water per link
    ( )

Section B: Structured questions[90 marks]

Answer all questions in the spaces provided.

1. 11

   This question is about rates of reaction.

   1. (a)

      On a gas-volume graph, a tangent at 40 s rises from 18 cm³ to 54 cm³ between 30 s and 60 s. Calculate the rate at 40 s.

      [2]
   2. (b)

      Explain why the tangent method is needed rather than dividing the total volume by the total time.

      [2]
   3. (c)

      Explain how a catalyst increases the rate of reaction.

      [3]
   4. (d)

      State what happens to the activation energy when temperature is increased. Explain your answer.

      [2]
2. 12

   This question is about equilibrium and the Haber process: N₂(g) + 3H₂(g) ⇌ 2NH₃(g), forward reaction exothermic.

   1. (a)

      State Le Chatelier’s principle.

      [2]
   2. (b)

      Predict and explain the effect on the equilibrium yield of ammonia of (i) increasing the pressure, (ii) increasing the temperature.

      [4]
   3. (c)

      Explain why the Haber process uses about 450 °C rather than a much lower temperature.

      [3]
3. 13

   This question is about yields and atom economy. In the Contact process stage 2SO₂ + O₂ ⇌ 2SO₃, the SO₃ (Mr = 80) is the desired product.

   1. (a)

      Calculate the atom economy of this reaction with respect to SO₃.

      [2]
   2. (b)

      Explain why the atom economy of this reaction is 100% even though its equilibrium yield is not.

      [2]
   3. (c)

      A different process makes a desired product (Mr 56) plus a waste co-product (Mr 44). Calculate its atom economy and state one way industry responds to a co-product.

      [4]
4. 14

   This question is about organic chemistry.

   1. (a)

      Complete the equation for cracking: C₉H₂₀ → C₃H₆ + ?

      [2]
   2. (b)

      Describe two differences between addition and condensation polymerisation.

      [2]
   3. (c)

      Name the functional groups in an amino acid and the polymer it forms.

      [2]
   4. (d)

      Explain why the alcohol ethanol can be described as a renewable fuel when made one way but not the other.

      [2]
5. 15

   This question is about chemical analysis.

   1. (a)

      An unknown solution gives a white precipitate with NaOH that dissolves in excess, and a cream precipitate with nitric acid followed by silver nitrate. Identify the ions present.

      [3]
   2. (b)

      Describe how flame emission spectroscopy identifies and quantifies metal ions in a water sample.

      [3]
   3. (c)

      Give two advantages of instrumental methods over manual tests.

      [2]
6. 16

   This question is about the atmosphere.

   1. (a)

      Describe how the atmosphere changed in each of the three phases of its evolution.

      [4]
   2. (b)

      Explain why the scientific evidence for human-caused climate change is considered robust.

      [3]
   3. (c)

      Explain two reasons why global carbon footprint reductions are difficult to achieve.

      [2]
7. 17

   This question is about using resources.

   1. (a)

      A steel pier is exposed to salt water. Explain why galvanising protects it better than paint alone.

      [3]
   2. (b)

      Explain why low-carbon steel is used for car bodies but high-carbon steel for cutting tools.

      [2]
   3. (c)

      Describe the structure of a composite material and name the matrix and reinforcement in steel-reinforced concrete.

      [2]
   4. (d)

      Describe one advantage and one disadvantage of desalination by reverse osmosis.

      [2]
8. 18

   This question is about the water-analysis practical. A student analyses 100 cm³ of a river sample.

   1. (a)

      Describe how to measure the mass of dissolved solids in the sample.

      [3]
   2. (b)

      The residue has a mass of 0.42 g. Calculate the dissolved solids in g/dm³.

      [2]
   3. (c)

      Describe how the student could obtain pure water from the sample and how its purity would be checked.

      [3]
   4. (d)

      State why the pH of the original sample should also be measured.

      [2]
9. 19

   This question is about fertilisers and water.

   1. (a)

      Write the equation for ammonia neutralising nitric acid and name the salt.

      [2]
   2. (b)

      Explain why phosphate rock must be treated with acid before use in fertilisers.

      [2]
   3. (c)

      Explain why the lab method for making a fertiliser salt differs from the industrial method.

      [3]
   4. (d)

      Evaluate the use of sewage-treated effluent compared with desalinated seawater as a water source for a dry region.

      [3]
10. 20

    This question is about analysis and materials.

    1. (a)

       Describe the tests that would confirm the presence of sulfate ions and chloride ions in separate solutions.

       [4]
    2. (b)

       Explain why the acids are added first in these tests.

       [2]
    3. (c)

       Compare thermosoftening and thermosetting polymers.

       [2]
    4. (d)

       Explain why carbon fibre composites are used for aircraft parts.

       [2]