Question

Which of the following salts when added to pure water will not alter its $p^H$ ?

• A. Ammonium acetate
• B. Ferric chloride
• C. Potassium cyanide
• D. Borax

Answer 1

Answer: (A)

Ammonium acetate

pH is independent of concentration for solutions of salts of weak acid and weak base.
$pH=7+\frac{1}{2}[p{K}_a-p{K}_b]$

Here Ammonium acetate is a salt of weak acid and weak base hence it acts as neutral solution and does not alter pH. Whereas other salt which are given either contain strong acid or strong base. Hence Ammonium acetate is a answer.