$H_2O_2$ cannot be used for which of the following purposes?

Which metal oxide among the following gives $H_2O_2$ on treatment with dilute acid?

$1 \ mL$ of $H_2O_2$ solution gives $10 \ mL$ of $O_2$ at $NTP$. It is ................ vol. $H_2O_2$.

Which of the following products are formed on the hydrolysis of $NaO_2$?

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.

Hydrogen peroxide converts manganese $(II)$ hydroxide rapidly into ' . . . . . . ' in alkaline medium. Which of the following compounds is suitable for filling in the blank?