Insulin contains $3.4\%$ sulfur. What is the minimum molecular weight of insulin?

Analysis of an organic compound shows $C = 40\%$,$H = 13.33\%$,and $N = 46.67\%$. Its empirical formula is ....

$A$ compound contains $8\%$ sulfur by weight. The minimum molecular weight of the compound is:

At $STP$,$2.8 \, L$ of a gaseous substance weighs $5.5 \, g$. If the compound contains $N$ and $O$ atoms,its molecular formula will be ..............

Hemoglobin contains $0.334 \% \, Fe$ by weight. If the molecular mass of hemoglobin is approximately $67200 \, g/mol$,determine the number of iron atoms in one molecule of hemoglobin. (Atomic mass of $Fe = 56 \, g/mol$)

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