Question

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

• A. A blue colour is obtained in ether due to the formation of $C{r}_2(S{O}_4{)}_3$
• B. A blue colour is obtained in ether due to formation of $Cr{O}_5$
• C. $Cr{O}_3$ is formed which dissolves in ether to give a blue colour
• D. Chromyl chloride is formed

Answer 1

The correct option is B A blue colour is obtained in ether due to formation of $Cr{O}_5$

Blue colour is obtained in ether due to the formation of $Cr{O}_5$ and this is soluble in ether.
$K_{2}C{r}_2{O}_7+H_{2}S{O}_4+4H_2{O}_2\to 2Cr{O}_5+K_{2}S{O}_4+5H_{2}O$