Law of reciprocal proportion source : Hemantmore.org.in

## Law of reciprocal proportion-

### Solution) source : Hemantmore.org.in

In Copper sulphide ,

mass of Cu  = 66.5  gm

mass of sulphur  = 100 – 66.5 = 33.5 gm

In Copper oxide,

mass of Cu  =  79.9  gm

mass of oxygen = 100 – 79.9 = 20.1   gm

Let us fix the mass of Cu  to 1 gm.

#### In Copper sulphide ,

66.5 gm Cu combine with sulphur = 33.5

1 gm Cu combine with sulphur = 33.5 / 66.5 = 0.5  gm

#### In , Copper oxide ,

79.9 gm of Cu combine with oxygen = 20.1

1  gm of Cu combine with oxygen  = 20.1 / 79.9 = 0.25 gm

The ratio of masses of sulphur and oxygen which combine with the fixed mass of Cu ( 1.0 gm) is ,

0.50 : 0.25  or 2 : 1

#### In SO3 ,

mass of sulphur = 40 gm

mass of oxygen  = 100 – 40 = 60 gm

The ratio of masses of  sulphur and oxygen  in SO3  is ,

40 : 60 = 2 : 3

### Solution )

In KCl ,

mass of K   = 52.0  gm

mass of Cl  = 100 – 52.0 = 48.0 gm

In KI ,

mass of  K  =  23.6  gm

mass of  I  = 100 – 23.6 = 76.4   gm

Let us fix the mass of K  to 1 gm.

#### In KCl ,

52.0 gm  K  combine with  Cl = 48

1 gm K combine with Cl = 48 / 52 = 0.92  gm

#### In  KI ,

23.6 gm of K combine with I = 76.4 gm

1  gm of K combine with I  = 76.4 / 23.6 = 3.24 gm

The ratio of masses of Cl and I which combine with the fixed mass of K ( 1.0 gm) is ,

0.92 : 3.24  or  1 : 3.5

#### In ICl ,

mass of  I  = 78.2 gm

mass of Cl  = 100 – 78.2 =  21.8 gm

The ratio of masses of  Cl  and I  in ICl  is ,

21.8 : 78.2 = 1 : 3.5