Rate of reaction
6.2What the syllabus asks of you
- Describe collision theory in terms of: (a) number of particles per unit volume (b) frequency of collisions between particles (c) kinetic energy of particles (d) activation energy, Ea
- State that a catalyst increases the rate of a reaction, decreases the activation energy, Ea, of a reaction and is unchanged at the end of a reaction
- Describe and explain the effect on the rate of reactions of: (a) changing the concentration of solutions (b) changing the pressure of gases (c) changing the surface area of solids (d) changing the temperature (e) adding or removing a catalyst, including enzymes using collision theory
- Describe and evaluate practical methods for investigating the rate of a reaction, including change in mass of a reactant or a product and the formation of a gas
- Interpret data, including graphs, from rate of reaction experiments
Read the notes first
Chapter 6: Rate of reaction
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Every question on Rate of reaction, untimed, marked as you go.
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59 questions
1May / June 2026 · Paper 11 · Q15Show mark scheme →
AExperiment 1 uses the same amount of magnesium as experiment 3, but twice the concentration of hydrochloric acid.
BExperiment 1 uses the same amounts of reactants as experiment 2, but at a higher temperature.
CExperiment 2 uses twice the amount of magnesium as experiment 3, but in the presence of a catalyst.
DExperiment 3 uses the same amounts of reactants as experiment 2, but with powdered magnesium instead of magnesium ribbon.
Mark scheme
2Oct / Nov 2025 · Paper 11 · Q15Show mark scheme →
AExperiment 1 is shown by curve X.
BExperiment 1 is shown by curve Y.
CExperiment 2 is shown by curve Y.
DExperiment 3 is shown by curve Z.
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3Oct / Nov 2025 · Paper 12 · Q15Show mark scheme →
Ausing a higher pressure in a gaseous reaction
Busing a lower temperature
Cusing a more dilute solution
Dusing larger pieces of a solid
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4Oct / Nov 2025 · Paper 12 · Q16Show mark scheme →
Aexperiment 1: W; experiment 2: Y
Bexperiment 1: W; experiment 2: Z
Cexperiment 1: X; experiment 2: Y
Dexperiment 1: X; experiment 2: Z
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5May / June 2025 · Paper 11 · Q17Show mark scheme →
AGraph A: mass of flask plus contents increases, experiment 1 curve above experiment 2
BGraph B: mass of flask plus contents increases, experiment 2 curve above experiment 1
CGraph C: mass of flask plus contents decreases, experiment 2 curve above experiment 1
DGraph D: mass of flask plus contents decreases, experiment 1 curve above experiment 2
Mark scheme
6May / June 2025 · Paper 12 · Q17Show mark scheme →
Ahigher frequency of collisions between particles | higher frequency of collisions between particles
Bhigher frequency of collisions between particles | the activation energy is decreased
Cthe activation energy is decreased | higher frequency of collisions between particles
Dthe activation energy is decreased | the activation energy is decreased
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7May / June 2025 · Paper 12 · Q18Show mark scheme →
AGraph A: dashed curve (experiment 2) rises faster and reaches the same final volume as the solid curve (experiment 1).
BGraph B: solid curve (experiment 1) rises faster and reaches the same final volume as the dashed curve (experiment 2).
CGraph C: solid curve (experiment 1) rises faster and reaches a higher final volume than the dashed curve (experiment 2).
DGraph D: solid curve (experiment 1) rises faster and reaches a higher final volume than the dashed curve (experiment 2).
Mark scheme
8Oct / Nov 2024 · Paper 11 · Q14Show mark scheme →
AThe rate of the reaction decreases. | The activation energy, Ea, decreases.
BThe rate of the reaction decreases. | The activation energy, Ea, increases.
CThe rate of the reaction increases. | The activation energy, Ea, decreases.
DThe rate of the reaction increases. | The activation energy, Ea, increases.
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9Oct / Nov 2024 · Paper 11 · Q15Show mark scheme →
AExperiments 1 and 2 both slow down as the reaction proceeds.
BExperiments 1 and 2 must both use acid of the same concentration.
CExperiments 1 and 2 must have been done at the same temperature.
DExperiment 2 uses larger lumps of calcium carbonate. All other conditions stay the same.
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10Oct / Nov 2024 · Paper 12 · Q17Show mark scheme →
Ax = 2, y = 3, T1 is higher than T2
Bx = 2, y = 3, T2 is higher than T1
Cx = 3, y = 2, T1 is higher than T2
Dx = 3, y = 2, T2 is higher than T1
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11May / June 2024 · Paper 11 · Q17Show mark scheme →
Aincreasing the acid concentration
Bincreasing the size of the solid particles
Cincreasing the surface area of the solid particles
Dincreasing the temperature
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12May / June 2024 · Paper 11 · Q18Show mark scheme →
AThe mass of aluminium added is 0.107 g.
BThe mass of aluminium added cannot be determined from the information given.
CThe highest rate of reaction is 71.5 cm3 / min.
DThe highest rate of reaction is when the acid concentration is highest.
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13May / June 2024 · Paper 12 · Q17Show mark scheme →
AA
BB
CC
DD
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14Oct / Nov 2023 · Paper 11 · Q17Show mark scheme →
A1, 2 and 3
B1 and 2 only
C1 and 3 only
D2 and 3 only
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15Oct / Nov 2023 · Paper 12 · Q16Show mark scheme →
Adisappearing cross / disappearing cross
Bdisappearing cross / loss of mass
Closs of mass / disappearing cross
Dloss of mass / loss of mass
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16May / June 2023 · Paper 11 · Q13Show mark scheme →
A1, 2 and 3
B1 and 2 only
C1 and 3 only
D2 and 3 only
Mark scheme
17May / June 2023 · Paper 11 · Q14Show mark scheme →
A1, 2 and 3
B1 and 3 only
C2 and 3 only
D3 only
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18May / June 2023 · Paper 12 · Q15Show mark scheme →
Aadding a catalyst to the reactants
Bdiluting the acid used in the reaction
Cstirring the reagents
Dusing magnesium powder instead of a strip of magnesium
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19May / June 2023 · Paper 12 · Q16Show mark scheme →
AA greater volume of acid is added.
BA higher concentration of acid is used.
CSmaller pieces of calcium carbonate are used.
DThe temperature of the acid is higher.
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20Oct / Nov 2022 · Paper 11 · Q21Show mark scheme →
ACopper acts as a biological catalyst in this reaction.
BCopper lowers the activation energy of this reaction.
CThe rate of the reaction is greater as the particle size of the zinc is greater.
DThe rate of the reaction is greater if the pressure is increased.
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21Oct / Nov 2022 · Paper 11 · Q22Show mark scheme →
Aconcentration of HCl decreases to zero; volume of hydrogen increases and levels off
Bconcentration of HCl decreases to zero; volume of hydrogen increases with increasing gradient
Cconcentration of HCl decreases and levels off above zero; volume of hydrogen increases with increasing gradient
Dconcentration of HCl decreases and levels off above zero; volume of hydrogen increases and levels off
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22Oct / Nov 2022 · Paper 12 · Q21Show mark scheme →
Adecrease, decrease, increase
Bdecrease, increase, decrease
Cincrease, decrease, increase
Dincrease, increase, decrease
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23Oct / Nov 2022 · Paper 12 · Q22Show mark scheme →
AA
BB
CC
DD
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24Oct / Nov 2022 · Paper 12 · Q23Show mark scheme →
Ato lower the activation energy for the reaction
Bto oxidise the sulfur dioxide
Cto reduce the sulfur dioxide
Dto shift the equilibrium to the right
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25May / June 2022 · Paper 11 · Q20Show mark scheme →
AAir contains only 21% oxygen so there is not enough oxygen for all the sulfur dioxide to react.
BOnly a small proportion of the sulfur dioxide and oxygen molecules have enough energy to react, even at high temperatures.
CThe reaction is exothermic and so at high temperatures the equilibrium shifts to the left.
DThe reaction is reversible and so products turn back to reactants; this happens more quickly at high temperatures.
Mark scheme
26May / June 2022 · Paper 11 · Q21Show mark scheme →
AAn enzyme is a biological catalyst that decreases the activation energy of a reaction.
BAn enzyme is a biological catalyst that increases the activation energy of a reaction.
CAn enzyme is a compound of a transition element that decreases the activation energy of a reaction.
DAn enzyme is a compound of a transition element that increases the activation energy of a reaction.
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27May / June 2022 · Paper 12 · Q20Show mark scheme →
A1 and 2
B1 only
C2 and 3
D3 only
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28May / June 2022 · Paper 12 · Q21Show mark scheme →
AP uses a catalyst and Q has a lower temperature.
BP uses 25 cm$^3$ of more concentrated acid and Q uses smaller pieces of solid.
CP uses a higher temperature and Q uses 25 cm$^3$ of more dilute acid.
DP uses smaller pieces of solid and Q uses larger pieces of solid.
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29Oct / Nov 2021 · Paper 12 · Q2Also set in Oct / Nov 2021 Paper 11Show mark scheme →
A1 only
B1 and 2 only
C2 and 3 only
D1, 2 and 3
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30Oct / Nov 2021 · Paper 12 · Q18Also set in Oct / Nov 2021 Paper 11, Oct / Nov 2018 Paper 11, Oct / Nov 2018 Paper 12Show mark scheme →
Aaddition of a catalyst
Bdecrease in temperature
Cincrease in concentration
Dincrease in pressure
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31Oct / Nov 2021 · Paper 12 · Q19Show mark scheme →
A1, 2 and 3
B1 and 2 only
C1 and 3 only
D2 and 3 only
Mark scheme
32May / June 2021 · Paper 11 · Q18Show mark scheme →
A1 and 3
B2, 3 and 4
C3 and 4 only
D4 only
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33May / June 2021 · Paper 12 · Q18Show mark scheme →
Ahigher frequency of collisions between particles | higher frequency of collisions between particles
Bhigher frequency of collisions between particles | the activation energy is decreased
Cthe activation energy is decreased | higher frequency of collisions between particles
Dthe activation energy is decreased | the activation energy is decreased
Mark scheme
34May / June 2021 · Paper 12 · Q19Also set in May / June 2021 Paper 11Show mark scheme →
Agraph A
Bgraph B
Cgraph C
Dgraph D
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35Oct / Nov 2020 · Paper 12 · Q2Also set in Oct / Nov 2020 Paper 11Show mark scheme →
A1, 2 and 3
B1 and 2 only
C2 only
D2 and 3 only
Mark scheme
36May / June 2020 · Paper 11 · Q17Show mark scheme →
AExperiment 1 is shown by curve X.
BExperiment 1 is shown by curve Y.
CExperiment 2 is shown by curve Y.
DExperiment 3 is shown by curve Z.
Mark scheme
37May / June 2020 · Paper 12 · Q2Show mark scheme →
Abalance, pipette, stop-clock
Bbalance, stop-clock, thermometer
Cburette, gas syringe, thermometer
Dmeasuring cylinder, stop-clock, thermometer
Mark scheme
38May / June 2020 · Paper 12 · Q18Show mark scheme →
Aadding a catalyst
Bincreasing the concentration of the acid
Cincreasing the surface area of the zinc
Dincreasing the temperature
Mark scheme
39Oct / Nov 2019 · Paper 11 · Q15Show mark scheme →
Ax = 2, y = 3, T1 is higher than T2
Bx = 2, y = 3, T2 is higher than T1
Cx = 3, y = 2, T1 is higher than T2
Dx = 3, y = 2, T2 is higher than T1
Mark scheme
40Oct / Nov 2019 · Paper 12 · Q17Show mark scheme →
A1, 2 and 3
B1 and 3 only
C2 and 3 only
D3 only
Mark scheme
41May / June 2019 · Paper 11 · Q18Show mark scheme →
AW X Y
BX Y W
CY W X
DY X W
Mark scheme
42May / June 2019 · Paper 12 · Q18Show mark scheme →
A1, 2 and 3
B1 and 2 only
C1 and 3 only
D2 and 3 only
Mark scheme
43May / June 2019 · Paper 12 · Q19Show mark scheme →
AThe catalyst increases the activation energy for the reaction.
BThe catalyst is used up during the reaction.
CThe gas syringe fills up more quickly when the catalyst is added.
DThe total amount of oxygen produced increases when the catalyst is added.
Mark scheme
44Oct / Nov 2018 · Paper 11 · Q18Show mark scheme →
Alumps of calcium carbonate with 1 mol / dm3 hydrochloric acid
Blumps of calcium carbonate with 2 mol / dm3 hydrochloric acid
Cpowdered calcium carbonate with 1 mol / dm3 hydrochloric acid
Dpowdered calcium carbonate with 2 mol / dm3 hydrochloric acid
Mark scheme
45May / June 2018 · Paper 11 · Q19Show mark scheme →
ABoth conclusions are correct and conclusion 2 explains conclusion 1.
BBoth conclusions are correct but conclusion 2 does not explain conclusion 1.
CConclusion 1 is correct but conclusion 2 is not correct.
DConclusion 2 is correct but conclusion 1 is not correct.
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46May / June 2018 · Paper 12 · Q19Show mark scheme →
AThe gas can be collected by displacing water from a measuring cylinder.
BThe mass of the reaction flask and its contents decreases as the reaction proceeds.
CThe rate of the reaction increases as time increases.
DThe reaction is still proceeding after eight minutes.
Mark scheme
47Oct / Nov 2017 · Paper 11 · Q20Show mark scheme →
A1 greater than 2 | 1 greater than 3
B1 greater than 2 | 3 greater than 1
C2 greater than 1 | 1 greater than 3
D2 greater than 1 | 3 greater than 1
Mark scheme
48Oct / Nov 2017 · Paper 12 · Q4Also set in Oct / Nov 2017 Paper 11Show mark scheme →
A1 and 2 only
B1 and 3
C1 and 4 only
D1, 2 and 4
Mark scheme
49Oct / Nov 2017 · Paper 12 · Q21Show mark scheme →
AGraph A
BGraph B
CGraph C
DGraph D
Mark scheme
50May / June 2017 · Paper 11 · Q2Show mark scheme →
Abalance and pipette
Bgas syringe and thermometer
Cstopclock and gas syringe
Dstopclock and pipette
Mark scheme
51May / June 2017 · Paper 11 · Q19Show mark scheme →
AGraph A: mass of flask and contents against time, curve rising from origin and levelling off
BGraph B: mass of flask and contents against time, curve rising from a non-zero value and levelling off
CGraph C: mass of flask and contents against time, curve decreasing from a maximum to zero
DGraph D: mass of flask and contents against time, curve decreasing from a maximum and levelling off at a non-zero value
Mark scheme
52May / June 2017 · Paper 11 · Q20Show mark scheme →
A2.96 × 10⁻³ mol / dm³ / s
B3.00 × 10⁻⁵ mol / dm³ / s
C4.00 × 10⁻⁵ mol / dm³ / s
D8.00 × 10⁻⁵ mol / dm³ / s
Mark scheme
53May / June 2017 · Paper 12 · Q16Show mark scheme →
AA lower concentration of acid was used in experiment 3 than in experiment 1.
BExperiment 4 was faster than experiment 3.
CThe acid used in experiment 2 was of a lower concentration than in experiment 1.
DThe temperature of the acid was the same in experiments 1 and 2.
Mark scheme
54Oct / Nov 2016 · Paper 11 · Q17Show mark scheme →
Abalance
Bgas syringe
Cmeasuring cylinder
Dstopwatch
Mark scheme
55Oct / Nov 2016 · Paper 11 · Q18Show mark scheme →
A1
B2
C3
D4
Mark scheme
56Oct / Nov 2016 · Paper 12 · Q2Show mark scheme →
A1, 2 and 3
B1 and 2 only
C2 only
D2 and 3 only
Mark scheme
57Oct / Nov 2016 · Paper 12 · Q16Show mark scheme →
A1, 2 and 3
B2 and 3 only
C2 only
D3 only
Mark scheme
58Oct / Nov 2016 · Paper 12 · Q17Show mark scheme →
Aexperiment 1: W; experiment 2: Y
Bexperiment 1: W; experiment 2: Z
Cexperiment 1: X; experiment 2: Y
Dexperiment 1: X; experiment 2: Z
Mark scheme
59May / June 2016 · Paper 11 · Q19Show mark scheme →
Agraph: mass decreasing rapidly then levelling off (exponential decay)
Bgraph: mass decreasing linearly to zero
Cgraph: mass decreasing rapidly then levelling off at a non-zero value
Dgraph: mass decreasing slowly then rapidly to zero
Mark scheme