Need a little help here...?

Question

When aluminum is heated with an excess of bromine, aluminum is formed. In a given experiment, 6.00 grams of aluminum is heated with an excess of bromine to yield 50.3 grams of aluminum bromide. Calculate the percent yield for this experiment.

Thanks in advance...

Answer 1

Like most stoichimetric questions, you have to get down to the moles.

6 grams of Aluminum (MW=26.98 g/gm-mol) is .22 moles

Aluminum Bromide is Al Br3 (MW = 266.69 g/gm-mol)

If 100% of the aluminum had reacted, we would get .22 moles of Al Br3 and that would mass (.22*266.69) 59.3 gm

We only got 50.3 grams so,

100* 50.3/59.3 = 84.8

84.8% yield

you might better check my arithmetic, and it wouldn't hurt to check my molecular weights either