What volume of 0.1M Of sulphuric acid is needed to neutralize 100cm³ of a solution of sodium carbonate of mass concentration 20gram over dm³

change Molarity to Normal solutions:

.1M H2SO4=.2N H2SO4
Normaliy of Na2CO3: 2*20/106 =.38N
the titration equation:
Va*Na=Vb*Nb
Va*.2=100cm^3*.38
Va=500*.38 cm^3