Question Detail
Question
What is the mass percent composition of chlorine in chloroethane (C₂H₅Cl)?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Molar mass = (2×12.01) + (5×1.008) + (1×35.45) = 24.02 + 5.04 + 35.45 = 64.51 g/mol. Mass of Cl = 35.45 g/mol. (35.45 / 64.51) × 100% = 54.95% ≈ 55.0%.
Hint
Calculate total molar mass and the mass contribution of chlorine.