Consider the following reaction at equilibrium. what will happen if fes2 is added to the reaction? 4fes2(s) + 11o2(g) ⇜ 2fe2o3(s) + 8so2(g) consider the following reaction at equilibrium. what will happen if is added to the reaction? 4(s) + 11(g) 2(s) + 8(g) the equilibrium constant will increase. the reaction will shift in the direction of the reactants. the reaction will shift in the direction of the products. no change in the position of the equilibrium is observed. the equilibrium constant will decrease.