Answer and Explanation:
- The Ka of a weak acid is a measure of its acidity and is defined as the equilibrium constant for the dissociation of the weak acid. It is the ratio of the concentrations of the products (H3O+ and the conjugate base) to the concentration of the reactant (the weak acid) at equilibrium. The higher the Ka value, the stronger the acid.
In this case, we were given the concentration of the weak acid and its pH. From the pH, we can calculate the concentration of H3O+ ions in the solution. Using this information, we can set up an ICE table to determine the equilibrium concentrations of the weak acid and its conjugate base. Finally, we can use the Ka expression to solve for the Ka of the weak acid.
- Therefore, the Ka of the weak acid is 1.5 x 10^(-5).