Question

Which of the following cannot be used as a test for $H_2{O}_2$?

• A. A paper dipped in $PbS$ (black) turns white when brought in contact with $H_2{O}_2$
• B. It liberates iodine from $KI$ solution which gives blue colour wiith starch solution
• C. It gives blue colour with $K_4\left[Fe\right(CN{)}_6].$
• D. It decolourises acidified $KMn{O}_4$

Answer 1

The correct option is C It gives blue colour with $K_4\left[Fe\right(CN{)}_6].$

It gives bright red colour with $K_4\left[Fe\right(CN{)}_6].$

$2K_4\left[Fe\right(CN{)}_6]+H_{2}S{O}_4+H_2{O}_2\to \underset{\text{bright red}}{2K_3\left[Fe\right(CN{)}_6]}+K_{2}S{O}_4+2H_{2}O$