$C_4H_6O_2$ does not represent :

An organic compound has a molar mass of $108 \ g \ mol^{-1}$. The atoms $C, H,$ and $N$ are present in the weight ratio of $9 : 1 : 3.5$. What is the molecular formula of the compound?

The percentage composition of $H, C$,and $O$ in $H_2C_2O_4$ is respectively:

The molecular formula of feldspar is

An oxygen-containing organic compound was found to contain $52 \%$ carbon and $13 \%$ hydrogen. Its vapour density is $23$. The compound reacts with sodium metal to liberate hydrogen. $A$ functional isomer of this compound is

The empirical formula of a compound is $CH_2O$ and its molecular mass is $90$. The molecular formula of the compound is: