2NaOH+H2SO4=Na2SO4+2H2O,设0.05mol/LH2SO4溶液为x mL
2 1
20*0.1 x*0.05
故2/20*0.1=1/x*0.05
解得:x=20
所以中和20mL0.1mol/LNaOH溶液需要0.05mol/LH2SO4溶液20mL