Question

A mixed oxide of iron and chromium is fused with sodium carbonate in the presence of air to form yellow coloured compound (a). On acidification of compound a forms and orange coloured compound (b) which is a strong oxidizing agent. Identify compound a and b and write a balanced chemical equation for formation of compound a.

Answer 1

Answer:

A - sodium chromate

B - sodium dichromate

Explanation:

iron chromate reacts with sodium carbonate in presence of air to form sodium chromate (A) which is a yellow coloured compound .

4FeO.Cr2O3 + 8Na2CO3 + 7O2----->

8Na2CrO4

sodium chromate (A) on acidification by conc. H2SO4 gives sodium dichromate (B) which is a strong oxidizing agent .

2Na2CrO4 + H2SO4-----> Na2Cr2O7 + Na2SO4 + H2O

i hope it will help's you.