The value of $x$ in $KAl(SO_4)_x \cdot 12 H_2O$ is $.....$

Insulin contains $3.4\%$ sulphur. The minimum molecular weight of insulin is

The formula which represents the simplest ratio of atoms of different elements present in a molecule of a substance is called:

The chemical formula for calcium pyrophosphate is $Ca_2P_2O_7$. What is the formula for ferric pyrophosphate?

What is the percentage of carbon in urea (in $\%$)? $(At. mass C = 12, H = 1, N = 14, O = 16)$

Haemoglobin contains $0.33 \%$ of iron by mass. The molecular mass of haemoglobin is $67200$. The number of iron atoms present in one molecule of haemoglobin is: (Atomic mass of $Fe = 56$)