In $CH_3CH_2Br$,the percentage of $Br$ is:

$A$ protein $'A'$ contains $0.30\, \%$ of glycine (molecular weight $75$). The minimum molar mass of the protein $'A'$ is $.......\, \times 10^{3} \, g\, mol^{-1}$ [nearest integer]

An organic compound has $42.1 \%$ carbon,$6.4 \%$ hydrogen and the remainder is oxygen. If its molecular weight is $342$,then its molecular formula is:

In an organic compound,the percentage of $C$ is $92.3 \%$. What is its empirical formula?

The molecular formula of feldspar is

An organic compound contains $C = 74.0\%$,$H = 8.65\%$ and $N = 17.3\%$. Its empirical formula is: