At 350 K, four independent homogeneous reactions (X, Y, Z, and W) were studied. The standard free-energy changes are:
Reaction X: ΔG° = −18.0 kJ·mol⁻¹
Reaction Y: ΔG° = +5.0 kJ·mol⁻¹
Reaction Z: ΔG° = −44.0 kJ·mol⁻¹
Reaction W: ΔG° = +0.8 kJ·mol⁻¹
(a) Calculate the equilibrium constant K for each of the four reactions at 350 K. Use R = 8.314 J·mol⁻¹·K⁻¹ and give each answer to three significant figures.
(b) Rank the reactions from the one most heavily favoring products at equilibrium to the one most heavily favoring reactants, based on your calculated K values.
(c) Determine how many orders of magnitude separate the largest K value from the smallest K value among the four reactions.
(d) Provide a quantitative explanation for the sensitivity of K to relatively small differences in ΔG° at this temperature.