Question

If the empirical formula of a compound is CH and it has a vapour density of 13, find the molecular formula of the compound. [C = 12, H = 1]

Answer 1

Given: Empirical formula = CH, vapour density = 13

Molecular weight = 2 x vapour density = 2 x 13 = 26

Empirical formula of a compound with molecular mass 26 is CH.

∴ Molecular formula of the given compound is 2 x (CH) = (CH)₂ = C₂H₂.