Question

When $H_2{O}_2$ is added to ice cold solution of acidified potassium dichromate in ether and the contents are shaken and allowed to stand :

• A. a blue colour is obtained in ether because of formation of $Cr{O}_5$
• B. a blue colour is obtained in ether because of formation of $Cr{O}_3$
• C. a blue colour is obtained in ether because of formation of $C{r}_2(S{O}_4{)}_3$
• D. chromyl chloride is formed

Answer 1

The correct option is A a blue colour is obtained in ether because of formation of $Cr{O}_5$

When $H_2{O}_2$ is added to ice cold solution of acidified potassium dichromate in ether and the contents are shaken and allowed to stand, a blue colour is obtained in ether because of formation of chromium peroxide $Cr{O}_5$.

$K_{2}C{r}_2{O}_7+H_{2}S{O}_4+4H_2{O}_2\to K_{2}S{O}_4+2Cr{O}_5+5H_{2}O$