An organic compound contains $C = 74.0\%$,$H = 8.65\%$ and $N = 17.3\%$. Its empirical formula is:

$20$ carat gold contains ...... $(\%)$ percent gold.

The empirical formula of a compound is $CH$. Its molecular weight is $78$. The molecular formula of the compound will be

Determine the molecular formula of an oxide of iron in which the mass per cent of iron and oxygen are $69.9$ and $30.1$ respectively. Given that the molar mass of the oxide is $159.69 \, g \, mol^{-1}$.

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

The molecular mass of an organic monobasic acid is $129$ and the value of $n$ is $2$. What is the empirical formula mass of the compound?