V(H3PO4) : V(NaOH)= Cн(NaOH) : Cн(H3PO4)
Сн(NaOH)=См(NaOH)=0,05*1=0,05моль/л;
5 : 6,5=0,05 : Cн(H3PO4)
Cн(H3PO4)=0,065моль/л;
См(H3PO4)=0,065/3=0,0217моль/л;
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