Catalysts in industry
4 marks · NormalRead the passage below and answer the questions that follow.
Explain how a catalyst lowers the activation energy of a reaction.
State what effect a catalyst has on the overall enthalpy change (ΔH) of the reaction.
Does the catalyst get used up in the reaction? Explain your answer.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) A catalyst provides an alternative reaction route with lower activation energy. · must show alternative route, lower activation energy
(b) No effect/the enthalpy change (ΔH) is unchanged. · must show ΔH same
(c) No, the catalyst is not used up; it remains unchanged at the end of the reaction. · must show not used up, remains unchanged
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Mentions catalyst provides an alternative pathway or reaction route.
A1 (a) · 1 mark · States that this route has a lower activation energy.
B1 (b) · 1 mark · States that the overall enthalpy change (ΔH) is unchanged by the catalyst.
B2 (c) · 1 mark · Says catalyst is not used up and/or remains unchanged at the end of the reaction.
Worked solution
(a) A catalyst works by providing an alternative reaction pathway with a lower activation energy. This means more particles have enough energy to react.
(b) The catalyst does not affect the overall enthalpy change (ΔH) of the reaction; ΔH stays the same.
(c) The catalyst is not used up in the reaction. It remains chemically unchanged after the reaction is complete.