Question

During the preparation of Mohr’s salt solution (Ferrous ammonium sulphate), which of the following acid is added to prevent hydrolysis of Fe2+ ion?

• A. dilute hydrochloric acid
• B. concentrated sulphuric acid
• C. dilute nitric acid
• D. dilute sulphuric acid

Answer 1

Answer: (D)

dilute sulphuric acid

Answer 2

Step 1: Hydrolysis of $Fe^{2+}$:
Dilute $H_2SO_4$ is used as it prevents hydrolysis and oxidation.