7. Consider the following chemical reaction. (12 pts) > 2 Al(s) +3 Cl2(g)- - - 2 AlCl3(s) (a) If
5.00 grams of Al reacts with 5.00 grams of Cl2, and 6.12 grams of 13 is produced, what is the
percent (%) yield of the reaction?
Solution
according to balanced reaction
2 x 27 g Al react with 3 x 71 g Cl2
5.00 g Al reacts with 5.00 x 3 x 71 / 2 x 27 = 19.72 g Cl2
but we have only 5.00 g Cl2. so Cl2 is limiting reagent
3 x 71 g Cl2 gives 2 x 133.34 g AlCl3
5.00 g Cl2 gives 5.00 x 2 x 133.34 / 3 x 71 = 6.26 g AlCl3
therotical yield = 6.26 g
actual yield = 6.12 g
% yield = (6.12 / 6.26) x 100
% yield = 97.8 %