$A$ sample of a pure compound contains $1.15 \ g$ of sodium,$3.01 \times 10^{22}$ atoms of carbon,and $0.1 \ mol$ of oxygen atoms. Its empirical formula is:

$A$ gas is found to contain $2.8 \ g$ of nitrogen and $3.2 \ g$ of oxygen. The simplest formula of the compound 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:

Determine the empirical formula of Kevlar,used in making bulletproof vests,which contains $70.6 \% \, C, \, 4.2 \% \, H, \, 11.8 \% \, N$ and $13.4 \% \, O$.

The percentage of $Se$ in peroxidase anhydrous enzyme is $0.5\%$ by weight (atomic weight $= 78.4$). Then,the minimum molecular weight of peroxidase anhydrous enzyme is:

Complete combustion of $750 \ g$ of an organic compound provides $420 \ g$ of $CO_2$ and $210 \ g$ of $H_2O$. The percentage composition of carbon and hydrogen in the organic compound is $15.3$ and ............. respectively. (Round off to the Nearest Integer)