Explain the relationship between the strength and number of the existing chemical bonds, the magnitude of the activation energy and the rate of a chemical reaction.

Which statement is true for the forward reaction?

A student compares two reactions at \ (25\,^{\circ}\text{C}\): Reaction 1 involves breaking one \(\text{C}−\text{Cl}\) bond (\ (338\,\text{kJ mol}^{-1}\)) in chloromethane, while Reaction 2 involves breaking one \(\text{C}−\text{I}\) bond (\ (240\,\text{kJ mol}^{-1}\)) in iodomethane. Both reactions proceed to form the same products under identical conditions. Explain how the difference in bond strength between the \(\text{C}−\text{Cl}\) and \(\text{C}−\text{I}\) bonds affects the activation energy and the rate of the two reactions.

A student investigates two different reactions at the same temperature. Reaction P involves breaking two C–H bonds (bond energy \(413\) kJ mol\(^{-1}\) each) in the rate-determining step. Reaction Q involves breaking one C–C bond (bond energy \(348\) kJ mol\(^{-1}\)) in the rate-determining step. Both reactions have similar overall enthalpy changes. Which statement correctly explains the relative rates of these reactions?