Question

Consider the bromination of anise with excess Br2.If you start with 0.127 g of anisole and end up with 0.145 g of o-bromoanisole, what is the percent yield of o-bromoanisole?

Answer 1

The percent yield of o-bromoanisole can be calculated using the formula:

percent yield = actual yield / theoretical yield x 100%

We can first calculate the theoretical yield of o-bromoanisole by using the molar ratio between anisole and o-bromoanisole, assuming that all the anisole reacted to form o-bromoanisole. The balanced chemical equation for the bromination of anisole is:

C6H5OCH3 + 2 Br2 → C6H4Br2OCH3 + 2 HBr

From the equation, we see that one mole of anisole produces one mole of o-bromoanisole. The molar mass of anisole is 150.21 g/mol, while the molar mass of o-bromoanisole is 243.05 g/mol. Therefore, the theoretical yield of o-bromoanisole is:

0.127 g / 150.21 g/mol x 243.05 g/mol = 0.206 g

The actual yield of o-bromoanisole is given as 0.145 g. Therefore, the percent yield is:

percent yield = 0.145 g / 0.206 g x 100% = 70.39%

The percent yield of o-bromoanisole is 70.39%.