Question Detail
Question
A compound has the empirical formula CH₂O and a molecular mass of 90.0 g/mol. How many atoms of oxygen are in one molecule of this compound?
Correct Answer
Option C is the correct answer.
Detailed Explanation
Empirical formula mass = 12 + 2 + 16 = 30 g/mol. n = 90/30 = 3. Molecular formula = (CH₂O)₃ = C₃H₆O₃. There are 3 oxygen atoms per molecule.
Hint
Find the factor (n) by which the empirical formula must be multiplied to get the molecular weight.