Question

Calculate the percentage of P2O5 in (NH4)2PO4

Answer 1

4 NH₃ + 3 H₂O + P₂O₅ → 2 (NH₄)₂HPO₄

2 moles of Diammonium phosphate is synthesized from 1 mole of Phophorous pentoxide.

1 mole of Diammonium phosphate can be synthesized from 1/2 mole of Phophorous pentoxide.

So, 1 mole Diammonium phosphate contains 1/2 mole of Phosphorous pentoxide.
132 gms of diammonium phosphate contains 71 gms of phosphorous pentoxide.
100 gms of diammonium phosphate contains 71 × 100 / 132 gms
                                                                = 53.787 gms of P₂O₅

Hence, 53.8 % (approximately) of P₂O₅ is present in (NH₄)₂PO₄