500 ml of 2M HCl +100ml of 2M H2SO4
Total milliequivalents of Hydronium ion will be → 500 x 2 + 100 x 4{since H2SO4 will give 2 H+} = 1400milliequivalents = 1.4 equivalents
The equivalents of OH− added in form of Monobasic alkali=1
Net after neutralization will be 0.4 equivalents of Hydronium ion.
30ml of this solution required 20ml of 143gm Na2CO3.xH2O in one-litre solution.
Now just equate both milliequivalents.
We know,
2H++Na2CO3→NaOH+CO2
THAT MEANS 2 HYDRONIUM IONS ARE NEEDED FOR EACH Na2CO3 MOLECULE
n factor for Na2CO3 is 2.
Molarity of Na2CO3 = 143106+18x
Normality = M x n factor =2M
0.4×30mL=2×143106+18x×20
∴ x = 10