The thermal decomposition of X₂(g) to form 2 X(g) has an overall enthalpy change of +10 kJ mol⁻¹, yet the reaction is observed to occur rapidly at room temperature in the absence of a catalyst.
Consider the kinetic and thermodynamic factors that influence the reaction.
(a) Describe qualitatively what a reaction-coordinate diagram for this decomposition must look like. In your description, include the relative positions of reactants and products, the number of transition states, and the approximate magnitude of the activation energy.
(b) Explain how the reaction can proceed rapidly even though it is endothermic overall.
(c) Predict the effect of increasing the temperature by 20 °C on (i) the rate of the reaction and (ii) the position of equilibrium. Provide reasoning for each prediction.
(d) Discuss whether introducing a suitable catalyst would alter the equilibrium constant for the reaction. Support your answer with thermodynamic reasoning.