中和20ml 10g/L的NaOH溶液,消耗某浓度的H2SO4溶液25ml,该H2SO4溶液的物质的量浓度是多少?

问题描述:

中和20ml 10g/L的NaOH溶液,消耗某浓度的H2SO4溶液25ml,该H2SO4溶液的物质的量浓度是多少?

m(NaOH)=20/1000 * 10g=0.2g
n(NaOH)=0.2/40 mol=0.005mol
n(H2SO4)=1/2*n(NaOH)=0.0025mol
n(H2SO4)=c(H2SO4)*V(H2SO4),V(H2SO4)=25/1000 L=0.025L
得c(H2SO4)=0.1mol/L