Question

A compound has a molar mass of 90. grams per mole and the empirical formula CH2O. What is the molecular formula of this compound?

Answer 1

Answer:

C₃H₆O₃

Explanation:

Data:

EF = CH₂O

MM = 90. g/mol

Calculations:

EF Mass = (12.01 + 2.016  + 16.00) u  = 30.03 u

The molecular formula is an integral multiple of the empirical formula.

MF = (EF)ₙ

$n = \dfrac{\text{MF Mass}}{\text{EF Mass }} = \dfrac{\text{90. u}}{\text{30.03 u}} = 3.00 \approx 3$

MF = (CH₂O)₃ = C₃H₆O₃