Question

The atomicity of a compound ${\text{C}}_{\text{a}}{\text{H}}_{\text{b}}$ is 6. If the ratio of carbon and hydrogen in the given compound is 1:2, then its empirical and molecular formula is _____ and ______ respectively.

Answer 1

Let’s take the total number of carbon atoms as x and hydrogen atoms as 2x. Therefore the atomicity will be x + 2x and this is equal to 6. On solving we will get x as 2. i.e the total number of carbon atoms is 2 and the total number of hydrogen atoms is 4. Hence the molecular formula will be $C_2{H}_4$ and thus the empirical formula will be: ${\mathrm{CH}}_2$