The percentage of $Se$ in peroxidase anhydrous enzyme is $0.5\%$ by weight (atomic weight $= 78.4$). Then,the minimum molecular weight of peroxidase anhydrous enzyme is:

Calculate the mass percent of calcium,phosphorus,and oxygen in calcium phosphate $Ca_{3}(PO_{4})_{2}$.

$A$ compound contains $10^{-2} \%$ of phosphorus. If the atomic mass of phosphorus is $31$,the molecular mass of the compound having one phosphorus atom per molecule is :-

An organic compound containing carbon and hydrogen has an empirical formula of $CH_2$. The mass of $1 \ L$ of this organic gas is equal to the mass of $1 \ L$ of $N_2$ gas at the same temperature and pressure. What is the molecular formula of the organic gas?

The molecular mass of an organic compound is $108 \ g \ mol^{-1}$. If $C, H,$ and $N$ atoms are present in the weight ratio of $9 : 1 : 3.5$,what is the molecular formula?

The molecular formula of potash alum is