## General Chemistry: Principles and Modern Applications (10th Edition)

(a) $$NH_3(g) + \frac 74 O_2(g) \leftrightharpoons \frac 32 H_2O(g) + NO_2(g)$$ (b) $$K_p'' = 1.91 \times 2.11 \times 10^{19} = 4.03 \times 10^{19}$$
1. Invert the second reaction: $$NO(g) + \frac 12 O_2(g) \leftrightharpoons NO_2(g)$$ $$K_p' = \frac{1}{0.524} = 1.91$$ 2. Add the reactions: $$NH_3(g) + \frac 54 O_2(g) + \frac 12 O_2(g) + NO(g) \leftrightharpoons NO(g) + \frac 32 H_2O(g) + NO_2(g)$$ $$NH_3(g) + \frac 74 O_2(g) \leftrightharpoons \frac 32 H_2O(g) + NO_2(g)$$ $$K_p'' = 1.91 \times 2.11 \times 10^{19} = 4.03 \times 10^{19}$$