A synthesis reaction
2 A(g) ⇌ B(g)
has ΔG° = +1.5 kJ mol⁻¹ at 298 K. Throughout this problem you may round the thermal energy term at 298 K to 2.5 kJ mol⁻¹ and work without a calculator.
(1) Estimate the magnitude of the equilibrium constant, K, at 298 K (order of magnitude is sufficient). Show your reasoning clearly.
(2) Based on your estimate in part (a), predict the mole-fraction of B present at equilibrium when the reaction is started with stoichiometric amounts of A only. Provide a brief justification.
(3) The reaction mixture is now heated to 350 K, and ΔG° is assumed to remain essentially the same. Will the equilibrium mole-fraction of B increase, decrease, or stay about the same? Support your answer with quantitative reasoning that does not require a calculator.