When orange solution containing Cr2072- ion is treated with an alkali, a yellow solution is formed and when H+ ions are added to yellow solution, an orange solution is obtained. Explain why does this happen?

NEETprep Answer: When orange solution containing Cr2O72-  ion is treated with an alkali, a yellow solution of Cr2O72- is obtained. On the same way  Cr2O72-          H+OH-       CrO42-
 Dischromate                     Chromate
(orange)                               (yellow)
when H+  ions are added to yellow solution, an orange solution is obtained due to interconversion.