Окислительно-восстановительная реакция: n2+o2=2no

Реакция соединения, окислительно-восстановительная, эндотермическая. Кислород - окислитель, азот - восстановитель.

N2+O2 = 2NO

N2(0) -4e = 2N(+2)   1   в-ль, ок-ие

O2(0) +4e = 2O(-2)  1   ок-ль, в-ие

Р2О5+3Н2О→2Н3РО4(1) Количества вещества Р2О5    2,84/142=0,02моль
масса ортофосфорной кислоты    0,02*98=1,96
массовая доля кислоты в новым растворе   (60*18+100*1,96)/62,84=20,3%
масса кислоты в этом растворе   62,84*0,203=12,76г
количества вщества кислоты  12,76/98=0,13моль
количества вещества щелочи 14/40=0,35 моль
 0,13       0,26          0,13
Н3РО4+2NaOH→Na2HPO4+H2O
 0,35-0,26=0,09 моль щелочи останется в избытке
0,09             0,09         0,09
Na2HPO4+NaOH→Na3PO4 +Н2О
в итоге образуется 0,13-0,09=0,04моль  Na2HPO4 и 0,09 моль Na3PO4 

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