$64 \, g$ of an organic compound contains $24 \, g$ of carbon,$8 \, g$ of hydrogen,and the rest oxygen. The empirical formula of the compound is

How many grams of oxygen are present in $32.2 \ g$ of $Na_2SO_4 \cdot 10H_2O$ (in $g$)?

Number of hydrogen atoms per molecule of a hydrocarbon $A$ having $85.8 \%$ carbon is $...............$. (Given : Molar mass of $A = 84 \ g \ mol^{-1}$ )

$A$ $1000 \ g$ sample of $NaOH$ contains $3 \ moles$ of $O$ atoms. What is the $Purity$ of $NaOH$ $\dots \dots \dots \dots \dots \dots \%$

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 $Fe = 56 \ g/mol$)

An organic compound contains carbon,hydrogen,and oxygen. Its elemental analysis gave $C = 38.71 \%$ and $H = 9.67 \%$. The empirical formula of the compound would be: