Empirical formula of a compound is $CH_2O$ and its vapour density is $30$. The molecular formula of the compound is:

An organic compound containing carbon and hydrogen has an empirical formula of $CH_2$. The mass of $1 \, L$ of this organic gas is equal to the mass of $1 \, L$ of $N_2$ gas at the same temperature and pressure. What is the molecular formula of the organic gas?

In a compound formed by element $X$ (atomic mass = $75$) and element $Y$ (atomic mass = $16$),if the percentage of $X$ is $75.8\%$,what will be its empirical formula?

$A$ gaseous hydrocarbon gives upon combustion $0.72 \ g$ of water and $3.08 \ g$ of $CO_{2}$. The empirical formula of the hydrocarbon is:

Which one has the highest percentage of nitrogen?

The empirical formula of Calgon is