The bleaching action of bleaching powder is due to the liberation of

Explain the following reactions:
$(a)$ Silicon is heated with methyl chloride at high temperature in the presence of copper.
$(b)$ Silicon dioxide is treated with hydrogen fluoride.
$(c)$ $CO$ is heated with $ZnO$.
$(d)$ Hydrated alumina is treated with aqueous $NaOH$ solution.

Which of the following halides is the most stable?

Which of the following has the lowest melting point?

The composition of common glass is:

Identify the correct statements from the following:
$(a)$ $CO_{2(s)}$ (dry ice) is used as a refrigerant for ice-cream and frozen food.
$(b)$ The structure of $C_{60}$ contains $20$ six-membered rings and $12$ five-membered rings.
$(c)$ $ZSM-5$,a type of zeolite,is used to convert alcohols into gasoline.
$(d)$ $CO$ is a colorless and odorless gas.