Practice R2.2 How fast? The rate of chemical change with authentic IB Chemistry exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like atomic structure, chemical reactions, and organic chemistry. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Paper
Level
Question 1
SLPaper 2
The reaction between sodium thiosulfate and hydrochloric acid forms a precipitate:
1.[2]
Describe a method to determine the rate of this reaction.
2.[1]
Suggest how temperature affects the time for the cross to disappear.
3.[2]
Explain this effect in terms of activation energy.
Question 2
SLPaper 2
Ammonia is formed by the Haber process:
The diagram below shows the energy profile of this reaction.
1.[1]
State what is meant by the term activation energy.
2.[2]
Identify whether the reaction is exothermic or endothermic and justify your answer using the diagram.
3.[1]
Suggest one reason why a high temperature is required for this reaction to proceed at a practical rate.
4.[2]
Explain how the use of a catalyst would affect the energy profile diagram.
5.[2]
The Haber process is a reversible reaction. State and explain one condition used in industry to increase the yield of ammonia.
Question 3
SLPaper 2
Hydrogen peroxide decomposes slowly at room temperature:
1.[1]
State one way to measure the rate of this reaction.
2.[1]
State how the rate of reaction changes as the reaction proceeds.
3.[2]
Explain your answer to part 2.
Question 4
SLPaper 2
The reaction between calcium carbonate and hydrochloric acid is represented by the following equation:
A student measured the volume of carbon dioxide produced over time at room temperature. The results are shown in the graph below.
1.[1]
State the meaning of the term rate of reaction.
2.[2]
Describe the shape of the graph.
3.[2]
Determine the average rate of reaction between 0 and 10 seconds if the volume of collected at 10 s is 22.5 cm³.
4.[1]
Suggest why the reaction eventually stops.
5.[2]
Explain, in terms of collision theory, why the rate of reaction is highest at the beginning.
6.[3]
Sketch how the graph would differ if the concentration of hydrochloric acid were doubled.
Question 5
SLPaper 1A
Several reactions of calcium carbonate with dilute hydrochloric acid are carried out at the same temperature.
Which reaction has the greatest rate?
| Answer | Concentration of HCl(aq) | Surface area of same mass of CaCO₃(s) |
|---|---|---|
| A | higher | larger |
| B | lower | smaller |
| C | lower | larger |
| D | higher | smaller |
Question 6
HLPaper 1A
Which change does not increase the initial rate of reaction when is added to excess ?
Question 7
HLPaper 1A
Copper catalyses the reaction between zinc and dilute sulfuric acid.
Why does copper affect the reaction?
Question 8
HLPaper 1A
Which change increases the rate of formation of hydrogen when zinc reacts with excess hydrochloric acid, assuming all other conditions remain the same?
Question 9
HLPaper 1A
The activation energy, of a reaction can be obtained from the rate constant, , and the absolute temperature, . Which graph of these quantities produces a straight line?
Question 10
HLPaper 1A
Which is true of an Arrhenius graph of ( -axis) against ?