Writing Equilibrium Constant Expressions 1. Write the equilibrium constant expression for each of the following react a. 2 H2O(g) = 2 H:0 (g) + O2@ b. 6 H.O. (g) = 6 H2O (g) + 3 02(g) c. The reverse of the reaction in part a d. 2 PbS (s) + 3 0,(g) = 2 PbO (s) +2 SO. (g) e. MgCl(s) = Mga- (aq) + 2 Ci (aq) f. The reverse of the reaction in parte