$120 \ g$ of an organic compound that contains only carbon and hydrogen gives $330 \ g$ of $CO_{2}$ and $270 \ g$ of water on complete combustion. The percentage of carbon and hydrogen,respectively,are ...... .

Calculate the mass percent of different elements present in sodium sulphate $(Na_{2}SO_{4})$.

$116 \ g$ of a substance upon dissociation reaction,yields $7.5 \ g$ of hydrogen,$60 \ g$ of oxygen and $48.5 \ g$ of carbon. Given that the atomic masses of $H, O$ and $C$ are $1, 16$ and $12$ respectively. The data agrees with how many formulae of the following?
$(A)$ $CH_3COOH$
$(B)$ $HCHO$
$(C)$ $CH_3OOCH_3$
$(D)$ $CH_3CHO$

If a compound on analysis was found to contain $C = 18.5\%$,$H = 1.55\%$,$Cl = 55.04\%$,and $O = 24.81\%$,then its empirical formula is:

$A$ substance contains $52.2\%$ carbon,$13\%$ hydrogen,and $34.8\%$ oxygen. If the vapor density of the substance is $46$,find its molecular formula.

An organic compound with a molecular weight of $60$ contains $C = 20\%$,$H = 6.67\%$,and $N = 46.67\%$,with the remainder being oxygen. Upon heating,the solid residue gives a violet color with alkaline copper sulfate solution. Identify the compound.