If 1 mole of ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$ 1s reacted with 1 mole of $\mathrm{A}(\mathrm{OH}{)}_3$ ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7+\mathrm{A}(\mathrm{OH}{)}_3⟶{\mathrm{AHP}}_2{\mathrm{O}}_7+3{\mathrm{H}}_2\mathrm{O}$ then:

(Atomic wt. of A= 69. P = 31)

 

equivalent weight of base is 40 .

 equivalent weight of base is 60 .

 if maximum oxidation number of A is + 5 then it can also participate in redox titration.

equivalent weight of ${\mathrm{H}}_4{\mathrm{P}}_2{\mathrm{O}}_7$ is 59.34.