Which of the following best explains why the enthalpy change, ΔH
CHEMISTRY · Single correct · A Level · Chemistry · Kinetics · Kinetics
Problem
Which of the following best explains why the enthalpy change, ΔH, for a reaction is the same for both the catalyzed and the uncatalyzed pathways?
(a) Because a catalyst is regenerated and not consumed, it cannot alter any thermodynamic quantity such as ΔH.
(b) The catalyst lowers the energies of both reactants and products by the same amount, so their energy difference, ΔH, stays the same.
(c) The catalyst affects only the energy of the transition state, leaving the energies of the reactants and products—and thus ΔH—unchanged.
(d) By increasing the rates of both the forward and reverse reactions equally, the catalyst prevents any net change in ΔH.