The percentage of nitrogen by mass in ammonium sulphate is closest to $.....$ $\%$ (atomic masses of $H = 1, N = 14, O = 16, S = 32$ ).

$A$ gaseous compound of nitrogen and hydrogen contains $12.5\%$ (by mass) of hydrogen. The density of the compound relative to hydrogen is $16$. The molecular formula of the compound is

What is the percentage by mass of oxygen in $NaOH$? (Atomic mass of $Na=23 \ u, O=16 \ u, H=1 \ u$)

Which of the following substances produces $17.6 \ g$ of $CO_2$ and $7.2 \ g$ of $H_2O$ upon complete combustion with excess oxygen?

$A$ compound contains $0.25\%$ of a metal with an atomic weight of $59$. If the compound contains one atom of the metal per molecule,what is the minimum molecular weight of the compound?

Quantitative analysis of an organic compound $(X)$ shows the following percentage composition: $C: 14.5\%$,$Cl: 64.46\%$,and $H: 1.8\%$. The empirical formula mass of the compound $(X)$ is $.......... \times 10^{-1}$. (Given molar mass in $g \ mol^{-1}$ of $C: 12, H: 1, O: 16, Cl: 35.5$)