1)3NaOH+H3PO4=Na3PO4+3H2O2) 2 NaOH + H3Po4 = Na2HPo4 + 2 H2O3) H3PO4 + NaOH → NaH2PO4 + H2On(NaOH)=m/M=0.4/23=0.02 мольn(H3PO4)=0.49/=0.005 моль1) n(H3PO4)=n(Na3PO4)=0.005 мольm(Na3PO4)=n*M=0.005*164=0.82г2) n(H3PO4)=n(Na2HPo4)=0.005 мольm(Na2HPo4)= 0.005*142=0.71г3) n(H3PO4)=n(NaH2PO4)=0.005мольm(NaH2PO4)=0.005*120=0.6г