A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The unknown compound is .
A) a weak base
B) a strong base
C) a weak acid
D) a strong acid
E) neither an acid nor a base

Question

Quizplus · Accepted Answer

The titration curve shows a gradual increase in pH from 2 to 8, indicating that the unknown compound is an acid. The steep rise in pH near the equivalence point suggests that the acid is a weak acid, as the addition of a small amount of NaOH caused a large increase in pH. Therefore, the best choice is C, a weak acid.

A 250 ML Sample of a Solution of an Unknown Compound