The empirical formula of a hydrocarbon containing $80\%$ carbon and $20\%$ hydrogen is:

$A$ transition metal $M$ forms a volatile chloride which has a vapour density of $94.8$. If it contains $74.75\%$ of chlorine,the formula of the metal chloride will be:

An organic compound contains carbon,hydrogen,and oxygen with percentages of $38.71\%$,$9.67\%$,and $51.62\%$ respectively. Determine the empirical formula of this compound.

The empirical formula of a crystalline iron compound is $Fe_2(SO_4)_3$. It is used in water and sewage treatment to remove suspended impurities. The percentage composition of iron,sulfur,and oxygen in this compound is respectively......

In an analysis,the ratio of iodine to oxygen in a certain substance is $254:80$. What will be the formula of this substance? (Atomic mass $I = 127$,$O = 16$)

An organic compound contains $C = 38.8\%$,$H = 16\%$ and $N = 45.2\%$. The empirical formula of the compound is: