The gas evolved when dil. sulphuric acid reacts with iron sulphide.

1. Hydrogen sulphide
2. Sulphur dioxide
3. Sulphur trioxide
4. Vapour of sulphuric acid.

In the given equation :

H₂S + 2H₂SO₄ ⟶ S + 2H₂O + SO₂

Identify the role played by conc. H₂SO₄

1. Non-volatile acid
2. Oxidising agent
3. Dehydrating agent
4. None of the above.

On passing SO₂ through chlorine water, the acid produced is :

1. H₂SO₃
2. HNO₃
3. H₂SO₄
4. H₂PO₄

When HCl is prepared by the reaction of NaCl with H₂SO₄, the property of H₂SO₄ exhibited is :

1. Dehydrating agent
2. Drying agent
3. Oxidising property
4. Non volatile acid