Question

27 g of Al will react completely with how many grams of oxygen?
(a) 8 g
(b) 16 g
(c) 32 g
(d) 24 g

Answer 1

4Al +3O2 ------------>2Al2O3
Now; From this...
108g of Al is completely react with 98g of oxgyen..
so..
108g Al -------->98g of O2
1g of Al ----------> 98g/108 of O2
27 g of Al ---------> (98g/108)×27g of oxygen..
which must be equal too 24g..
answer :d) 24g