Question

Suppose Y -> X is spontaneous due to the lower energy of X (and -ΔG), a significant initial excess of X would make the __________ reaction favoured to reach the equilibrium state predicted by the difference in energy between X & Y.

Answer 1

When Y spontaneously reacts to form a lower energy X resulting in a negative Gibbs free energy, the reverse reaction (X → Y) becomes favored if there's an initial excess of X, as the system strives to reach equilibrium by minimizing its free energy.

Step-by-step explanation:

If Y → X is a spontaneous reaction due to the lower energy of X and a negative change in Gibbs free energy (-ΔG), then the reverse reaction of X → Y would be favored to reach the equilibrium state when there is a significant initial excess of X. This happens because reactions proceed spontaneously in a direction that will establish equilibrium, where the system's free energy is minimized.

If a system consists of reactants and products in nonequilibrium amounts (Q ≠ K), the reaction will move in the direction necessary to reach equilibrium. So, if X is in excess, the system will shift towards forming more Y to reduce the free energy and attain equilibrium. This is in keeping with Le Chatelier's Principle, which states that a system at equilibrium when subjected to a change will respond to minimize that change.