If we want to study the relative arrangement of atoms in a molecule,we study:

$A$ hydrocarbon contains $75\%$ carbon by mass. What is its empirical formula?

The percentage of nitrogen in urea is about

Urea is a better fertilizer than ammonium sulphate because

If the weight percentage of $Se$ (at. wt. $78.4$) in peroxidase anhydrous enzyme is $0.5 \%$,what is the minimum molecular weight of the enzyme?

$A$ protein $'A'$ contains $0.30\, \%$ of glycine (molecular weight $75$). The minimum molar mass of the protein $'A'$ is $.......\, \times 10^{3} \, g\, mol^{-1}$ [nearest integer]