Phosphoric acid (H3PO4) is widely used to make fertilizers and can be prepared in a two-step process.StepI:P4+5O2⟶P4O10StepII:P4O10+6H2O⟶4H3PO4We allow 310 g of phosphorus to react with excess oxygen, which forms tetraphosphorus deoxide (P4O10) in 50% yield. In the step II, 25% yield of H3PO4 is obtained.
(Atomic weight in amu of P=31,H=1,O=16)Assuming 100% yield, the number of moles of H3PO4 is :