Question

How will you convert potassium chromate to potassium dichromate ? Mention the colour change involved in the reaction.

Answer 1

Potassium chromate on reaction with sulphuric acid gives potassium dichromate.

$\underset{\left(\text{Potassium chromate}\right)}{2K_{2}Cr{O}_4}+H_{2}S{O}_4⟶\underset{\left(\text{Potassium dichromate}\right)}{K_2{Cr}_2{O}_7}+K_{2}S{O}_4+H_{2}O$

In the above reaction the colour changes fro yellow to orange red due to formation of potassium dichromate.