(a)[5]
Methane reacts with chlorine to form chloromethane. This reaction is exothermic.\n\n$\text{CH}_4(g) + \text{Cl}_2(g) \rightarrow \text{CH}_3\text{Cl}(g) + \text{HCl}(g)$\n\nUsing the axes shown in Fig. 6.1, draw the reaction pathway diagram for this reaction. Make sure you label the axes, reactants, products, enthalpy change of reaction $\Delta H$ and activation energy $E_a$.
(b)[3]
Hydrogen iodide breaks down to form hydrogen and iodine.\n\n$2\text{HI} \rightarrow \text{H-H} + \text{I-I}$\n\nCalculate the enthalpy change of this reaction using the bond energies in Table 6.1.