Question 6
HA student investigates how the size of pieces of calcium carbonate affects the rate of its reaction with dilute hydrochloric acid.
The student starts with a cube of calcium carbonate with sides of 2.0 cm.
a.[2]
Calculate the surface area to volume ratio of the cube.
b.[2]
The diagram shows how the student cuts the cube into 8 smaller cubes. Each small cube has sides of 1.0 cm.
Calculate the surface area to volume ratio of the 8 small cubes.
c.[2]
The 8 small cubes react faster with the acid than the large cube.
Explain why. Use your answers to (a) and (b).
d.[2]
Nitrogen monoxide reacts with oxygen.
2NO+O2→2NO2 2\mathrm{NO} + \mathrm{O_{2}} \rightarrow 2\mathrm{NO_{2}} 2NO+O2→2NO2Explain how increasing the pressure of the gases affects the rate of this reaction.
e.[2]
A student says, "Increasing the temperature increases the rate of a reaction only because the particles collide more often."
Explain why this statement is incomplete.
5.2 Controlling reactions Questions
56 exam-style questions on OCR GCSE Chemistry 5.2 Controlling reactions, covering 5.2.1 Measuring and interpreting rate of reaction, 5.2.2 Factors affecting rate and collision theory, and 5.2.3 Catalysts, activation energy and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.