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?

Question

Quizplus · Accepted Answer

To calculate the percent by mass of bromine, we need to find the molar mass of the two bromine atoms present in dibromoethane and divide it by the total molar mass of the compound.

Molar mass of Br2 = 2 x 79.904 g/mol = 159.808 g/mol
Percent by mass of bromine = (159.808 g/mol / 187.9 g/mol) x 100% = 85.05%

Therefore, the correct answer is C) 85.05%.

The Molar Mass of an Insecticide,dibromoethane,is 187