Question

On shaking $H_2{O}_2$ with acidified potassium dichromate and ether, ethereal layer becomes:

• A. green
• B. red
• C. blue
• D. brown

Answer 1

Answer: (C)

blue

The reaction between acidified potassium dichromate, $H_2{O}_2$ and ether can be given as:

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

(Blue)

Here, $K_{2}C{r}_2{O}_7$ is oxidized to $Cr{O}_5$ which is blue in colour. This $Cr{O}_5$ gives blue colour to the ethereal layer.

Thus the answer is (C) blue.