The Titration of a Weak Acid, HA ( K _a

Multiple Choice

The titration of a weak acid, HA ( K _a = 1.0×10 ^{- 4}) , with NaOH requires 40.0 mL to reach the equivalence point. In order to calculate the pH of the system after 20 mL of NaOH is added, the best strategy is to recognize that the system is

A) a strong acid
B) a weak acid
C) a buffer
D) neutral
E) a weak base