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?

The weight percentage of $C$ and $H$ in a hydrocarbon is in the ratio of $4: 1$. What is its empirical formula?

One mole of one of the sodium salts listed below,having carbon content close to $14.3 \%$,produces $1 \ mole$ of carbon dioxide upon heating (atomic mass of $Na = 23, H = 1, C = 12, O = 16$). The salt is:

Calculate the mass of $Ca$ in $g$ present in $Ca(NO_3)_2$ that contains $20 \ g$ of nitrogen.

In which of the following pairs of compounds is the ratio of $C$,$H$,and $O$ the same?

If $0.0833 \, \text{mol}$ of a carbohydrate contains $1 \, \text{g}$ of hydrogen and its empirical formula is $CH_2O$,what is its molecular formula?