The total weight of mixture is 1.20 g.
Volume of the solution = 100mL
Volume the solution taken for neutralisation V2= 20mL
Volume of HCl solution V1=40cm3= 40mL
Normality of HCl N1= 0.1N
Now. for calculating the mass of Na2CO3
N1×V1=N2×V2
0.1×40=N2×20
N2= 0.2N
It means that 1L of solution contains 0.2 gram equivalent.
∴ 0.1L of solution contains 0.02 gram equivalent.
In a mixture, number of gram equivalent = sum of g equivalent of (K2CO3+Na2CO3)
We know that Number of gram equivalent = massequivalent mass
and
Equivalent mass = molar massValency Factor
Equivalent mass of Na2CO3 =1062=53g
Equivalent mass of K2CO3 =1382=69g
Let weightof Na2CO3=xgm.
weight of K2CO3=(1.2−x)gm
0.02 = x53+1.2−x69
On calculating we get , x= 0.59gm = 0.6 gm
Weight of Na2CO3=0.6gm.
Weight of K2CO3=0.6gm