The molar mass of an insecticide, dibromoethane, is 187.9 g/mol. Its
molecular formula is C2H4Br2. What percent by mass of bromine does
dibromoethane contain?
OA) 42.52%
OB) 2.14%
OC) 85.05%
OD) 12.78%
E) 6.39%