Question

When dilute sulphuric acid reacts with iron sulphide, the gas evolved is ………..

• A. Hydrogen sulphide
• B. Sulphur dioxide
• C. Sulphur trioxide
• D. Vapour of Sulphuric acid

Answer 1

The correct option is A

Hydrogen sulphide

The reaction between dilute Sulphuric acid and Iron sulphide:

1. Dilute Sulphuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ reacts with Iron sulphide $\left(\mathrm{FeS}\right)$ to give Iron (II) sluphate $\left({\mathrm{FeSO}}_4\right)$ and Hydrogen sulphide $\left({\mathrm{H}}_2\mathrm{S}\right)$ gas as a product.
2. During this reaction, hydrogen sulphide $\left({\mathrm{H}}_2\mathrm{S}\right)$ gas is liberated with effervescence.

• Balanced chemical equation :

$\underset{\mathrm{Suphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}+\underset{\mathrm{Iron}\left(\mathrm{II}\right)\mathrm{sulphide}}{\mathrm{FeS}\left(\mathrm{s}\right)}\to \underset{\mathrm{Iron}\left(\mathrm{II}\right)\mathrm{sulphate}}{{\mathrm{FeSO}}_4\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrogen}\mathrm{sulphide}\mathrm{gas}}{{\mathrm{H}}_2\mathrm{S}\left(\mathrm{g}\right)}$

Hence, the correct option is (A).