Which of the following acts as both an oxidizing agent and a reducing agent?

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

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 structure of $H_2O_2$ is

Which of the following statements is correct?

Which method is currently used for the industrial production of $H_2O_2$?