When the substances in the equation below are at equilibrium, at pressure P and temperature T, the equilibrium can be shifted to favor the products by CuO(s)+ H₂(g) H₂O(g)+ Cu(s)$\Delta$Hº_rxn = -2.0 kJ/mol

Question

Quizplus · Accepted Answer

According to Le Chatelier's principle, a decrease in temperature will favor the exothermic reaction in order to compensate for the decrease in energy. In this case, the formation of Cu and CO from CuO and H₂O is exothermic, so decreasing the temperature will shift the equilibrium to favor the products. None of the other options will have an effect on the equilibrium position. Increasing pressure (options A and B) will favor the side with fewer moles of gas, which in this case is the reactant side. Allowing some gases to escape (option D) will simply reestablish the equilibrium concentration of the remaining gases, without shifting the equilibrium position. Adding a catalyst (option E) will only increase the rate of the reaction, but not favor either the reactants or products.

When the Substances in the Equation Below Are at Equilibrium Δ\DeltaΔ

When the Substances in the Equation Below Are at Equilibrium $\Delta$