Question

Answer the question by selecting the appropriate option given below:

Assertion (A): When ferrous sulphate is heated, it decomposes to form anhydrous ferric oxide, sulphur dioxide, and sulphur trioxide.

Reason (R): Heating the salt provides energy which breaks ferrous sulphate into simpler compounds.

[0.8 mark]

• A. Both A and R are true, and R is the correct explanation of A.
• B. Both A and R are true, and R is not the correct explanation of A.
• C. A is true, but R is false.
• D. A is false, but R is true.

Answer 1

The correct option is A Both A and R are true, and R is the correct explanation of A.

Upon heating, ferrous sulphate undergoes a decomposition reaction to produce ferric oxide, sulphur dioxide, and sulphur trioxide. Ferrous sulphate initially loses its water of crystallisation to form anhydrous ferrous sulphate which then undergoes decomposition to form the products.

$FeS{O}_4.7H_{2}O\stackrel{\Delta }{\to }FeS{O}_4+7H_{2}O$

$FeS{O}_4\left(s\right)\stackrel{\Delta }{\to }F{e}_2{O}_3\left(s\right)+S{O}_2\left(g\right)+S{O}_3\left(g\right)$

The heat energy provided during this reaction provides the energy for the breakdown of ferrous sulphate to simpler compounds.