A compound has the empirical formula C2H40, and its formula mass is 88 g. What is the subscript for oxygen in the molecular formula? *

2

Explanation:

The molecular formula can be derived from the empirical formula of a compound and the molecular mass as follows:

(C2H4O)n = 88g/mol

Where;

C = 12, H = 1, O = 16

{12(2) + 1(4) + 16}n = 88g/mol

{24 + 4 + 16}n = 88

(44)n = 88

44n = 88

Divide both sides by 44

n = 88/44

n = 2

The molecular formula is: (C2H4O)n

= (C2H4O)2

= C4H8O2

According to the question asked, oxygen has a subscript of 2 in the molecular formula.