Select the correct statement.

Rohan heard that instructions were given to the laboratory attendant to store a particular chemical,i.e.,keep it in the dark room,add some urea in it,and keep it away from dust. This chemical acts as an oxidising as well as a reducing agent in both acidic and alkaline media. This chemical is important for use in the pollution control treatment of domestic and industrial effluents.
$(i)$ Write the name of this compound.
$(ii)$ Explain why such precautions are taken for storing this chemical.

The oxide that gives $H_2O_2$ on treatment with a dilute acid is

Which of the following gives $H_2O_2$ on hydrolysis?

Acidified solution of chromic acid on treatment with hydrogen peroxide yields:

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