Question

If 112 g of iron (Fe) combines with 24 g of oxygen (O2), how much iron oxide is formed?

Answer 1

112 gram of iron and 24 gram of oxygen then answer is 88

Answer 2

Amount of iron oxide formed when 112 g of Fe reacts with 24g of O2 is 108 grams.

Reaction of above problem is

2Fe+O2------->2FeO

So 2 moles of iron react with 1 mole of oxygen to give 2 moles of FeO.

That is 112 g of iron reacts with 32 g of oxygen but since oxygen is 24 grams as given hence oxygen is limiting reagent.

●A limiting reagent is one which is present in limited amount and the concentration of product formed depends on limiting reagent.

●So here amount of iron oxide formed depends on amount of oxygen.

●According to equation we have

32g of oxygen gives 2×(56+16)g of FeO

32 g of O2 gives 144 grams of FeO

1g of O2 gives 144/32 g of FeO

So,24 g of O2 gives (144/32)×24g

24 g of O2 gives 108g of FeO.