1.5) Energy Changes - EXAM QUESTIONS

Question 1

What is meant by the term ‘activation energy’?

Answer 1

The minimum energy (needed by particles)… [1]
…for a reaction to occur. [1]

Question 2

Describe the differences between a fuel cell and an alkaline chemical cell.

[2 marks]

Answer 2

An alkaline chemical cell contains a store of the reactants but a fuel cell must be supplied with fuel and oxygen continuously. [1]
An alkaline chemical cell will eventually run out of reactants and cannot be recharged but a fuel cell can be used continuously. [1]

Question 3

Answer 3

Question 4

The temperature rises when different metal powders are added to dilute sulfuric acid. Give one other observation that might be made when the metals are added to the acid. How would this observation be different for the different metals?

[2 marks]

Answer 4

Bubbles of gas. [1]
More bubbles seen with a more reactive metal. [1]