Question

why is freshly prepared ferrous sulphate solution used as a reagent for brown ring test?

Answer 1

it is more active........

Answer 2

● Answer -
Ferrous sulphate is freshly prepared to avoid conversion of Fe2+ to Fe3+.

● Explaination -
- Ferrous ion is used in brown-ring test for identification of NO3-.
- Ferrous ion on standing changes to ferric ion.
Fe2+ ---> Fe3+ + e-
- This ferric ion is not suitable agent for reaction.
- Thus, ferrous sulphate should be freshly prepared before use.

Hope this helps you...