Which gases are evolved during complete decomposition of ferrous sulphate crystals?

Correct option is A

The correct answer is (A) Both SO₂ and SO₃.

Explanation:
During the complete decomposition of ferrous sulfate crystals (FeSO₄), both sulfur dioxide (SO₂) and sulfur trioxide (SO₃) gases are evolved.

Incorrect Options Explanations:

• (B) Only SO₃: Sulfur trioxide is not the only gas formed during decomposition; SO₂ is also produced.
• (C) O₂: Oxygen gas is not produced in the decomposition of ferrous sulfate.
• (D) Only SO₂: Sulfur dioxide is produced, but sulfur trioxide is also released.

Information Booster:

• Decomposition Reaction: 2FeSO₄ → Fe₂O₃ + SO₂ + SO₃
• Conditions: Occurs when ferrous sulfate is heated strongly.