Consider a general reversible reaction . Which of the following conclusions logically follow from th — Chemical Equilibrium Chemistry Question
Question
Consider a general reversible reaction $aA + bB \rightleftharpoons cC + dD$. Which of the following conclusions logically follow from the relationship between Gibbs free energy and the reaction quotient ($Q$)?
💡 Solution & Explanation
By $\Delta G = \Delta G^\circ + RT \ln Q = -RT \ln K + RT \ln Q = RT \ln(Q/K)$. If $Q < K$, $\ln(Q/K)$ is negative, so $\Delta G < 0$ (forward spontaneous). If $Q > K$, $\Delta G > 0$ (backward spontaneous). If $Q = K$, $\Delta G = 0$ (equilibrium). Standard free energy $\Delta G^\circ$ only determines the equilibrium position ($K$), not the instantaneous direction for any arbitrary $Q$ (D is false).