$C_4H_6O_2$ does not represent :

The percentage of $P_2O_5$ in diammonium hydrogen phosphate $(NH_4)_2HPO_4$ is

$A$ compound contains $2.2 \ g$ of phosphorus and $1.24 \ g$ of sulfur. What is its empirical formula?

$A$ hydrocarbon contains $85.7 \% C$. If $42 \, mg$ of the compound contains $3.01 \times 10^{20}$ molecules,the molecular formula of the compound will be

$A$ compound contains $10^{-2} \%$ of phosphorus. If the atomic mass of phosphorus is $31$,the molecular mass of the compound having one phosphorus atom per molecule is :-

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.