(a(i))[1]
State the compound that is heated together with long-chain hydrocarbons so that more useful smaller alkanes and alkenes are produced.
(a(ii))[2]
Describe how photochemical smog is formed during the combustion of petrol in an internal combustion engine.
(b)
$\text{C}_4\text{H}_8$ reacts with excess $\text{H}_2$ to form $\text{C}_4\text{H}_{10}$. Reaction 1: $\text{C}_4\text{H}_8 + \text{H}_2 \rightarrow \text{C}_4\text{H}_{10}$.
(b(i))[1]
Name one catalyst used in reaction 1.
(b(ii))[1]
Define the term activation energy, $E_A$.
(b(iii))[2]
Fig. 3.1 shows the Boltzmann distribution for the reaction mixture in reaction 1. Use the Boltzmann distribution to explain how adding a catalyst affects the rate of reaction.