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) O 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

The addition of NaOH to a buffer solution causes the pH to increase slightly because the NaOH reacts with the weak acid present in the buffer solution. In this case, the weak acid is hydrazoic acid. Thus, the correct answer is D) hydrazoic acid. The azide ion (Choice C) is the conjugate base of sodium azide, but it is not the weak acid in this buffer solution. Choice E is not the correct answer because the question specifically states that the pH of the buffer solution does increase slightly with the addition of NaOH.

A Solution Is Prepared by Dissolving 0