Effect of Temperature on Reaction Rates & the Concept of Activation Energy (Cambridge (CIE) A Level Chemistry): Exam Questions

A reversible reaction is shown.

A + B ⇌ C + D

The reaction pathway diagram for this reaction is shown in Fig. 1.1.

Fig. 1.1

Use Fig. 1.1 to deduce whether the forward reaction is exothermic or endothermic. Explain your answer.

Define the term activation energy, E_a.

Use Fig. 1.1 to determine the activation energy for the forward reaction and for the reverse reaction.

activation energy of the forward reaction = .............................. kJ mol^-1

activation energy of the reverse reaction = .............................. kJ mol^-1

Fig. 1.2 shows the reaction pathway diagram for the same reaction in the presence of a catalyst.

Fig. 1.2

Use Fig. 1.2 to explain how the addition of a catalyst increases the rate of reaction.