What is the mass of $$33.6 \mathrm{~dm}^3$$ of methane gas at S.T.P.?

An element with BCC structure has edge length of $$500 \mathrm{~pm}$$. If it's density is $$4 \mathrm{~g} \mathrm{~cm}^{-3}$$, find atomic mass of the element?

Identify the reagent (A) used in the following reaction.

What is the product formed when side chain chlorination of toluene is carried out followed by acid hydrolysis at $$373 \mathrm{~K}$$ ?