Question

A compound on analysis gave the following percentage composition C = 54.54%, H, 9.09% 0 = 36.36. The vapour density of the compound was found to be 44. Find out the molecular formula of the compound. 

Answer 1

Calculation of empirical formula

Empirical formula is C₂ H₄ O.

Calculation of Molecular formula

Empirical formula mass = 12 x 2 + 1 x 4 + 16 x 1 = 44 

Molecular mass = 2 x Vapour density 

= 2 x 44 = 88

Molecular formula = Empirical formula x n

= C₂ H₄ O x 2 

= C₄ H₈ O₂