Question

Find the equilibrium constants, Kp, for the following equilibria, (i) NO(g) + ½ O2(g) ⇄ NO2(g), Kp = ? (ii) NO2(g) ⇄ NO(g) + ½ O2(g), Kp = ?, given the equilibrium constant, Kp, for the reaction: 2NO (g) + O2(g) ⇄ 2NO2(g) Kp= 100 at the same temperature

Answer 1

Answer:

Equilibrium constant for the 1st reaction is 10 and for the 2nd reaction is 0.1

Explanation:

$2NO+O_{2}\rightleftharpoons 2NO_{2}$

$K_{p}=\frac{P_{NO_{2}}^{2}}{P_{NO}^{2}\times P_{O_{2}}}=100$

(i) $NO+\frac{1}{2}O_{2}\rightleftharpoons NO_{2}$

Equilibrium constant, $K_{p1}=\frac{P_{NO_{2}}}{P_{NO}\times P_{O_{2}}^{\frac{1}{2}}}=\sqrt{K_{p}}=\sqrt{100}=10$

(ii) $NO_{2}\rightleftharpoons NO+\frac{1}{2}O_{2}$

$K_{p2}=\frac{P_{NO}\times P_{O_{2}}^{\frac{1}{2}}}{P_{NO_{2}}}=\frac{1}{K_{p1}}=\frac{1}{10}=0.1$