An organic compound has $C = 60\%$,$H = 13.3\%$ and $O = 26.7\%$. Its empirical formula will be

Hemoglobin in red blood cells contains $0.33\%$ iron by mass. The molecular weight of hemoglobin is $67000$. What is the number of iron atoms present in each molecule of hemoglobin? (Atomic mass of $Fe = 56 \ g/mol$)

The ratio of the mass percentages of $C$ and $H$ and $C$ and $O$ of a saturated acyclic organic compound $X$ are $4 : 1$ and $3 : 4$ respectively. Then,the moles of oxygen gas required for complete combustion of two moles of organic compound $X$ is

$0.5 \ g$ of an organic compound $(X)$ with $60 \%$ carbon will produce $........ \times 10^{-1} \ g$ of $CO_2$ on complete combustion.

$0.765 \ g$ of an acid gives $0.535 \ g$ of $CO_2$ and $0.13 \ g$ of $H_2O$. The ratio of the percentage of $C$ and $H$ is:

$A$ 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