Question 10.5: Effect of Changes in Concentration on Equilibrium An importa...
Effect of Changes in Concentration on Equilibrium
An important reaction in the body fluids is
H_{2} CO_{3}(aq)+H_{2} O(l) \rightleftarrows HCO_{3}{}^{-}(a q)+H_{3} O^{+}(aq)Use Le Châtelier’s principle to predict whether the system shifts in the direction of products or reactants for each of the following:
a. adding some H_{2} CO_{3}(aq)
b. removing some HCO_{3}{}^{-}(aq)
c. adding some H_{3} O^{+}(aq)
According to Le Châtelier’s principle, when stress is applied to a reaction at equilibrium, the system shifts to relieve that stress.
a. When the concentration of the reactant H_{2} CO_{3} increases, the rate of the forward reaction increases to shift the system in the direction of the products until equilibrium is reestablished.
b. When the concentration of the product HCO_{3}{}^{-}decreases, the rate of the reverse reaction decreases. The system shifts in the direction of the products until equilibrium is reestablished.
c. When the concentration of the product H_{3} O^{+} increases, the rate of the reverse reaction increases. The system shifts in the direction of the reactants until equilibrium is reestablished.