CHEMISTRY! Conservation of mass!!!!!! Help?

Question

Aluminum metal reacts with bromine and produces aluminum bromide. A sample of 27 g of aluminum yields 266.7 g of aluminum bromide.

How many grams of bromine react with 15 grams of aluminum?

Please explain thoroughly.

i WILL reward the best answer and give you your points.

Answer 1

2Al + 6Br2 -> 2AlBr3; so al/Br2=3moles Al / 1 mole of Br2

Too much info! Weed out the superficial - both of the first two bits of data!

15 g Al/ 27 g/mole*3mole of Br2/mole Al * 2*79.90 gBr2/mole Br2 =

solve

Answer 2

2 Al + 3 Br2 -------> 2 AlBr3

from balanced equation:

2mole of Al reacts with 3mole of Br2 to produce 2 moles of AlBr3

moles of Al = moles of AlBr3

moles of Br2 = 3/2 moles of Al

so ....

moles of Al  in 15g= 15/26.98 =0.56 mol

moles of Br2 = 3/2 X 0.56 =0.834 mol

mass= moles X molecular weight

mass of  Br2 =0.834 X (79.9X2)=133.27 g

your answer :

15 g of Al reacts with 133.27 g of Br2