A solution is prepared by dissolving 0.23 mol of benzoic acid and 0.27 mol of sodium benzoate in water sufficient to yield 1.00 L of solution.The addition of 0.05 mol of NaOH to this buffer solution causes the pH to increase slightly. The pH does not increase drastically because the NaOH reacts with the ________ present in the buffer solution. The K_a of benzoic acid is 6.3 × 10^-5. A)H₂O B)H₃O⁺ C)benzoate D)benzoic acid E)This is a buffer solution: the pH does not change upon addition of acid or base.

Question

Quizplus · Accepted Answer

The addition of NaOH causes the pH to increase slightly because it reacts with the weak acid in the buffer solution, which is benzoic acid (H₃O). NaOH is a strong base and will react with the weak acid to form its conjugate base (benzoate, ⁺) and water. This reaction consumes some of the NaOH, preventing a drastic increase in pH. Thus, the correct answer is choice D, benzoic acid.

A Solution Is Prepared by Dissolving 0