If you start with 75 mg of anisole and excess bromine, and the bromination occurs 3 times, then what is your theoretical yield (in mg) of tribromoanisole?

239.6 mg is the  theoretical yield of tribromoanisole.

Explanation:

Mass of anisole = 75 mg = 0.075 g

1 mg = 0.001 g

Moles of anisole =

According to reaction, 1 mole anisole gives 1 mole of tribromoanisole.

Then 0.0006944 mole of anisole will give:

of tribromoanisole

Mass of 0.0006944 mole of tribromoanisole:

0.0006944 mol × 345 g/mol = 0.2396 g = 239.6 mg

239.6 mg is the  theoretical yield of tribromoanisole.