Question

1 mol of iron (Fe) reacts completely with 0.65 mol O, to
give a mixture of only FeO and Fe,0,. Mole ratio of
ferrous oxide to ferric oxide is :
(A) 3:2
(B) 4:3
(C) 20:13
(D) none of these​

Answer 1

Answer:

4:3

Explanation:

1 mol of iron (Fe) reacts completely with 0.65 mol O, to

give a mixture of only FeO and Fe,0,. Mole ratio of

ferrous oxide to ferric oxide is :

2Fe + O2 ==> 2FeO

a a/2 moles a

4Fe +3O2 ===> 2Fe2O3

b 3b/4 moles b/2

a+ b = 1

a/2 + 3b/4 = 0.65

or 1/2 a+ 1/2 b = 1/2 ( I substitute the first equation with 1/2)

a/2 + 3b/4 = 0.65

==> b = 0.6 moles

a= 0.4 moles

--> moles FeO = 0.4 moles

moles Fe2O3 = 0.6/2 = 0.3 moles

===>

Ratio = 0.4/0.3 = 4/3