KHP is slightly acidic, and it is often used as a primary standard for acid–base titrations because it is solid and air-stable, making it easy to weigh accurately. It is also used as a primary standard for calibrating pH meters because, besides the properties just mentioned, its pH in solution is very stable.

Application

Potassium hydrogen phthalate is used as a primary standard for acid- base titrations as well as for calibrating pH meters. It acts as a buffer in pH determination. It finds application as a useful standard for total organic carbon testing.