Answer
(a) $$K_p = \frac{P_{CH_4}P_{H_2S}^2}{P_{CS_2}P_{H_2}^4}$$
(b) $$K_p = P_{O_2}^{1/2} = \sqrt{P_{O_2}}$$
(c) $$K_p = P_{CO_2}P_{H_2O}$$
Work Step by Step
1. The $K_p$ expression follows this pattern:
$aA + bB \leftrightharpoons cC + dD$
$$K_p =\frac{P_{product}}{P_{reactants}} = \frac{P_C^cP_D^d}{P_A^aP_B^b}$$
Where solids and liquids do not appear on the expression.
(a) $$K_p = \frac{P_{CH_4}P_{H_2S}^2}{P_{CS_2}P_{H_2}^4}$$
(b) $$K_p = P_{O_2}^{1/2} = \sqrt{P_{O_2}}$$
(c) $$K_p = P_{CO_2}P_{H_2O}$$
