For the reaction
Al+O2→Al2O3
(The equation is not balanced)
54 g of Al is reacted with 67.4 litre at STP. 76.5 g of Al2O3 was obtained. The percentage yield of the product obtained is
The balanced chemical equation is
4Al+3O2→2Al2O3
108 g of Al on reaction with 67.4 litre of oxygen at STP gives 204 g of alumina.
54 g of Al should react with 33.7 litre of oxygen and give 102 g of alumina.
Hence the amount of excess reagent = 67.4 - 33.7 = 33.7 litre
Theoretical yield = 102 g
Experimental yield = 76.5 g
Percentage yield =experimental yieldtheoretical yield×100
=76.5102×100
=75%