A solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide 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 hydrazoic acid is 1.9 × 10^-5. A)H₂O B)H₃O⁺ C)azide D)hydrazoic acid E)This is a buffer solution: the pH does not change upon addition of acid or base.

Question

Quizplus · Accepted Answer

Hydrazoic acid is the weak acid component of the buffer solution. When a small amount of strong base such as NaOH is added to the buffer, it reacts with the weak acid component (hydrazoic acid) to form its conjugate base (azide) and water. This helps to minimize the increase in pH, which is the main function of a buffer solution. Therefore, the correct answer is D.

A Solution Is Prepared by Dissolving 0