The simplest formula of a compound containing $50\%$ of element $X$ (at. wt. $= 10$) and $50\%$ of element $Y$ (at. wt. $= 20$) is

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?

$A$ compound contains $75.8\%$ of $X$ and $24.2\%$ of $Y$ by mass. If the atomic weights of $X$ and $Y$ are $24$ and $16$ respectively,find the empirical formula of the compound.

$A$ compound has $50\%$ carbon,$50\%$ oxygen and its approximate molecular weight is $290$. Its molecular formula is

An organic compound containing $C$,$H$,and $N$ gave the following analysis: $C = 40\%$,$H = 13.33\%$,and $N = 46.67\%$. Its empirical formula would be:

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: