Orange colour of dichromate ion changes to yellow in alkaline medium.

Question

Account for the following:

Orange colour of dichromate ion changes to yellow in alkaline medium.

Answer 1

Dichromate ion changes to chromate ion/OH^-

Cr₂O₇^2- (orange) CrO₄^2- (yellow).

Detailed Answer:

When an alkali is added to an orange solution of dichromate, a yellow solution is obtained due to the formation of chromate ions.