You are given a solution of the weak base Novocain, Nvc. Its pH is 11.00. You add to the solution a small amount of a salt containing the conjugate acid of Novocain, NvcH⁺. Which statement is true? A) The pH and the pOH remain unchanged. B) The pH and the pOH both decrease. C) The pH and the pOH both increase. D) The pH increases and pOH decreases. E) The pH decreases and the pOH increases.

Question

Quizplus · Accepted Answer

Adding a salt containing the conjugate acid of Novocain will increase the concentration of the conjugate acid in the solution. This will shift the equilibrium towards the weak base (Novocain), consuming some of the OH- ions in the solution and thereby lowering the pH. Since pH and pOH are inversely related (pH + pOH = 14 at 25°C), as the pH decreases, the pOH increases.

You Are Given a Solution of the Weak Base Novocain