$A$ hydrocarbon contains $75\%$ carbon by mass. What is its empirical formula?

$A$ compound has an empirical formula $C_2H_4O$. An independent analysis gave a value of $132.16$ for its molecular mass. What is the correct molecular formula?

The empirical formula of Calgon is

An organic compound contains carbon,hydrogen,and oxygen with percentages of $38.71\%$,$9.67\%$,and $51.62\%$ respectively. Determine the empirical formula of this compound.

Find the empirical formula of the compound if $M = 68 \%$ (Atomic mass $= 34$) and the remaining $32 \%$ is oxygen:

The empirical formula of a compound is $CH_2O$ and its molecular weight is $120$. The molecular formula of the compound is: