Question

Consider the following equilibrium reaction having gaseous reactants and products.4HCl + O2 ⇌ 2H2O + Cl2Which of the following would result from increasing only the concentration of oxygen? The concentration of hydrochloric acid increases. The rate of forward reaction increases. The rate of backward reaction increases. The concentration of water vapor decreases.

Answer 1

First, we explain what Le Châtelier's principle states:

When there is a dynamic equilibrium, and this equilibrium is disturbed by an external factor, it will shift in the direction that can cancel the effect of the external factor to reattain the equilibrium.

The external factors could be temperature, pressure, volume, and concentration.

According to this exercise, we increase the concentration of O2 (reactant), so the equilibrium will be shifted to the side of products to suppress the effect of increasing the concentration. Therefore, the rate of the forward reaction increases.

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It could also be explained with rate = f(concentration)

The forward rate depends on the concentration of reactants, so it will increase if the concentration of O2 increases.

Answer: The rate of the forward reaction increases.