Question

Calculate the empirical and molecular formula of a compound containing 76.6% carbon, 6.38 % hydrogen and rest oxygen its vapour density is 47.

Answer 1

Empirical formula = C₆H₆ O 

Va-pour density 47 

∴ Molecular mass = 2 x vapor density 

= 2 x 47 

= 94 

Molecular formula Empirical formula x n 

Molecular mass x n 

n = (Molecular mass) / (Empirical formula mass) 

= 94/94 

= 1 

∴ Molecular formula = C₆H₆O