An organic compound was found to contain $40.0 \% C$ and $6.66 \% H$. Find its molecular formula (molar mass $= 180$).

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

$0.5 \ g$ of hydrocarbon gave $0.9 \ g$ of water on combustion. The percentage of carbon in the hydrocarbon is:

On combustion,$0.210 \ g$ of an organic compound containing $C$,$H$,and $O$ gave $0.127 \ g$ $H_2O$ and $0.307 \ g$ $CO_2$. The percentages of hydrogen and oxygen in the given organic compound respectively are $:$

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

An organic substance $(80 \ g)$ on analysis was found to contain $C = 24 \ g$,$H = 4 \ g$,and $O = 32 \ g$. What is its empirical formula?