Decomposition of $H_2O_2$ is prevented by

$H_2O_2$ has a:

$10 \, mL$ of $H_2O_2$ solution $(d = 1 \, g/mL)$ when reacted with $KI$ solution produced $0.5 \, g$ of iodine. Calculate the percentage purity of $H_2O_2$ .............. $\%$

What is the $O-O-H$ bond angle in the solid form of $H_2O_2$ (in $^{\circ}$)?

Assertion $:$ Amount of $H_2O_2$ in a sample can be determined by treating $H_2O_2$ solution with $KI$ and followed by titration of liberated $I_2$ with sodium thiosulphate.
Reason $:$ In this titration,an intense blue colour appears which disappears at the end point.

Which of the following molecules can act as an oxidizing as well as a reducing agent?