Question

In the following diagram, if acetic acid of same concentration is taken in place of dilute sulphuric acid, then

• A. Same amount of H$_2$ gas will be evolved.
• B. H$_2$ gas will not be evolved.
• C. The amount of H$_2$ gas evolved will be less.
• D. In place of H$_2$ gas, O$_2$ gas will be evolved.

Hint:

Strong acid → More H$_2$ gas. Weak acid (like acetic acid) → Less H$_2$ gas.

Answer 1

The Correct Option is C

Concept: Metals react with acids to produce hydrogen gas. The rate and amount of hydrogen evolved depend on the strength of the acid. Explanation:

• Dilute sulphuric acid is a strong acid and ionizes completely in water.
• Acetic acid is a weak acid and ionizes only partially.
• Fewer H$^+$ ions are available in acetic acid compared to sulphuric acid.
• Hence, less hydrogen gas will be produced when acetic acid is used.

Conclusion: Since acetic acid is a weak acid, the amount of hydrogen gas evolved will be less compared to dilute sulphuric acid.