Question

When a green coloured crystal is heated reddish brown solid forms with the release of pungent gas name the crystal and the solid obtained

Answer 1

Hello!
This is Abhinav Singh

When we heat ferrous sulphate in presence of air it decomposes into 3 following compounds-

• Ferric oxide (Brown solid)
• Sulphur dioxide ( pungent smell)
• Sulphur trioxide

The reaction is-

2FeSO4 = Fe2O3 + SO2 + SO3

Answer 2

Answer:

When a green coloured crystal is heated reddish brown solid forms with the release of pungent gas; hence here the green color substance must be ferrous sulphate and when it is heated it forms ferric oxide which is red in color with Sulphur trioxide and Sulphur dioxide gas. Here both of these gases have pungent smell.  

The balance chemical equation for the thermal decomposition of ferrous sulphate can be written as:

$\bold{2 \mathrm{FeSO}_{4} \rightarrow \mathrm{Fe}_{2} \mathrm{O}_{3}+\mathrm{SO}_{2}+\mathrm{SO}_{3}}$