A reaction at 300 K with consist of 3 moles of A(g), 6 moles of B(g) and 3 moles of C(g). If A, B an — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Equilibrium constant $\ln K_c = -\frac{\Delta G^\circ}{RT} = \frac{1743}{8.3 \times 300} = \frac{1743}{2490} = 0.7 = \ln 2 \implies K_c = 2$. At equilibrium, $[\text{A}]=3, [\text{B}]=6, [\text{C}]=3$. Checking the reaction profiles, only $2\text{A} \rightleftharpoons \text{B} + \text{C}$ yields $K_c = \frac{[\text{B}][\text{C}]}{[\text{A}]^2} = \frac{6 \times 3}{3^2} = 2$.