Describe the preparation of potassium dichromate from iron chromite ore. What is the effect of increasing pH on a solution of potassium dichromate?

Explanation

For preparation : See page no. 216
In aqueous solution, the dichromate and chromate ions are in equilibrium. On increasing .the .(p)^(16). of the solution by adding alkali, the orange coloured dichromate ions are converted into yellow coloured chromate ions. .(Cr)_(2) (O)_(7)^(2-) stackrel(OH)^(+)/(H)^(*) 2 (CrO)_(4)^(2-^(2).
te Cliromate ion (Orange)