An organic compound contains $C = 38.8\%$,$H = 16\%$ and $N = 45.2\%$. The empirical formula of the compound is:

An organic substance $(80 \ g)$ on analysis was found to contain $C = 24 \ g$,$H = 4 \ g$,and $O = 32 \ g$. What is its empirical formula?

An organic compound contains $C$,$H$ and $S$. The minimum molecular weight of the compound containing $8\%$ sulphur is........$g\,mol^{-1}$ (atomic weight of $S = 32\,amu$)

$A$ compound containing $Xe$ and $F$ has $63.8\%$ of $Xe$ by mass. Calculate the oxidation number of $Xe$ in this compound.

$A$ compound contains $2.2 \ g$ of phosphorus and $1.24 \ g$ of sulfur. What is its empirical formula?

$A$ sample of calcium carbonate $(CaCO_3)$ has the following percentage composition: $Ca = 40\%$; $C = 12\%$; $O = 48\%$. If the law of constant proportions is true,then the weight of calcium in $4 \, g$ of a sample of calcium carbonate obtained from another source will be $... \, g$.