(N/A) $(i)$ The name of the compound is hydrogen peroxide,$H_2O_2$. It acts as an oxidising agent as well as a reducing agent in both acidic and basic media.
$(ii)$ $H_2O_2$ is unstable and decomposes in the presence of light and dust particles. Urea is added as a stabilizer (negative catalyst) to inhibit its decomposition.
The decomposition reaction is: $2H_2O_{2(aq)} \xrightarrow{h\nu} 2H_2O_{(l)} + O_{2(g)}$
Due to its strong oxidising properties,$H_2O_2$ is used in pollution control to oxidise harmful cyanides and foul-smelling sulphides present in domestic and industrial effluents. It also aids in sewage treatment by supplying oxygen for the oxidation of organic matter.