Question

The mass of oxygen which separately combines with a fixed mass of iron to form iron (IIl) oxide and iron (ll) oxide respectively are in the simple ratio
a) 1:2
b)2,4
c)3:8
d) 2:6​

Answer 1

Answer:

c

Explanation:

Answer 2

Answer:

Explanation:

Iron from two oxides:

Mass of iron in both are equal say y gm

Mass of O

2

​

in 2nd oxide is x gm

Mass of O

2

​

in 1st oxide is

3

2x

​

gm

Now, equal gm equivalent of reactant always react.

∴ No. of equivalence =

Eq. wt

reactant

​

Eq. wt=

valency

molar mass

​

∴ No. of g.eq=

Molar mass

Given wt

​

×valency

∴ For 1st oxide

56

x

​

×v

1

​

=

3×8

2x

​

−−−−(i)

For 2nd oxide

56

x

​

×v

2

​

=

8

x

​

−−−−(ii)

Divide both equations

56×x×v

2

​

x×v

1

​

×56

​

=

3×8×x

2x×8

​

∴

v

2

​

v

1

​

​

=

3

2

​

The ratio of the valency of iron in 1st and 2nd oxide is 2:3