An organic compound contains $60\ \%\ C$,$4.48\ \%\ H$,and $35.5\ \%\ O$. Its empirical formula is:

$120 \ g$ of an organic compound that contains only carbon and hydrogen gives $330 \ g$ of $CO_{2}$ and $270 \ g$ of water on complete combustion. The percentage of carbon and hydrogen,respectively,are ...... .

The empirical formula of a compound is $C_2H_5O$ and its vapour density is $45$. What is the molecular formula of the compound?

How many grams of oxygen are present in $32.2 \ g$ of $Na_2SO_4 \cdot 10H_2O$ (in $g$)?

Substances $X$ and $Y$ have the same mass. If their atomic weights are $30$ and $20$ respectively,and the molecular weight of the compound is $120$,what is the molecular formula of the compound?

In a compound,$C$,$H$,and $N$ atoms are present in $9 : 1 : 3.5$ by weight. The molecular weight of the compound is $108$. What is the molecular formula of the compound?