Question

Which of the following acts as a pickling agent?

• A. HCL
• B. HNO₂
• C. HNO₃
• D. H₂SO₄

Answer 1

The correct option is D

H₂SO₄

The correct option is D.

Explanation of correct option:

1. To remove the oxide film on the metallic sheet, dip the sheet in an H₂SO₄ solution.
2. This metal surface treatment is called pickling.

Explanation of incorrect options:

Option A

1. HCl is secreted by the parietal cells of the stomach,

Option B

1. Nitrous acid is used in making azo dyes.

Option C

1. Nitric acid is a highly corrosive mineral acid.

Final answer: H₂SO acts as a pickling agent.