A compound has an empirical formula of AB and a molar mass of 90 g/mol. What is its

molecular formula? (Molar mass of AB = 30 g/mol)

A3B3

Explanation:

Molecular formula = n x empirical formula

(AB) n = 90

MM of AB = 30 g/mol

30n = 90

Divide both side by the coefficient n i. e 30

n = 90/30 = 3

Molecular formula = n x empirical formula

Molecular formula = n x (AB)

Molecular formula = 3 (AB) = A3B3