用石墨电极电解AGNO3溶液,在阳极收集0.4gO2,中和电解时生成的酸需250mlNAOH溶液,NAOH物质量浓度是

n(O2)=0.4/32=0.0125mol4AgNO3+2H2O=4Ag+O2↑+4HNO3 1 40.0125mol n(HNO3)n(HNO3)=0.05molHNO3+NaOH=NaNO3+H2O1 10.05mol n(NaOH)n(NaOH)=0.05molc(NaOH)=n/V=0.05/0.25=0.2mol/L