Question

A solution containing HCl and the weak acid HClO_2 has a pH of 2.4. Enough KOH(aq) is added to the solution to increase the pH to 10.5. The amount of which of the following species increases as the KOH(aq) is added? a. Cl^- b. H^+ c. ClO_2^d. HClO_2

Answer 1

The correct answer is (c) ClO2-.

When KOH is added to the solution, it will react with the HCl to form KCl and H2O. This will decrease the concentration of H+ in the solution, which will cause the pH to increase.

The KOH will also react with the HClO2 to form KClO2 and H2O. However, the HClO2 is a weak acid, so the reaction will not go to completion. This means that some of the HClO2 will remain in solution.

As the pH of the solution increases, the equilibrium of the following reaction will shift to the right:

HClO2 + H2O ⇌ ClO2- + H3O+

This means that the concentration of ClO2- will increase as the pH of the solution increases.

Therefore, the amount of ClO2- increases as the KOH(aq) is added.

Step-by-step explanation: