The molar mass of the insecticide dibromoethane is 187.9. Its molecular formula is C₂H₄Br₂. What percent by mass of bromine does dibromoethane contain?

Question

Quizplus · Accepted Answer

The molar mass of Br is approximately 79.9 g/mol. Since there are two bromine atoms in C2H4Br2, the total mass of bromine is 2 * 79.9 = 159.8 g/mol. The percent by mass of bromine is (159.8 / 187.9) * 100% = 85.0%.

The Molar Mass of the Insecticide Dibromoethane Is 187