When orange solution containing Cr 2 O 7 2– ion is treated with an alkali, a yellow solution is formed and when H + ions are added to yellow solution, an orangesolution is obtained. Explain why does this happen?

Question

Philoid · Accepted Answer

The following reaction takes place when Cr₂O₇^2–is treated with an alkali:

(orange) Cr₂O₇^2–+ OH^-→ 2CrO₄^2-(yellow)

When the yellow solution is treated with an acid, we get back the orange solution:

(yellow)2CrO₄^2- +2H⁺→Cr₂O₇^2–(orange)+ H₂O

This reaction is reversible under proper conditions.

When orange solution containing Cr2O72– ion is treated with an alkali, a yellow solution is formed and when H+ ions are added to yellow solution, an orangesolution is obtained. Explain why does this happen?

When orange solution containing Cr₂O₇^2– ion is treated with an alkali, a yellow solution is formed and when H⁺ ions are added to yellow solution, an orangesolution is obtained. Explain why does this happen?