The balanced chemical equation between phosphorus and oxygen can be given as,
[tex] 4 P(s) + 5 O_{2}(g) -->2 P_{2}O_{5}(s) [/tex][tex] 8.50 mol O_{2} * \frac{2 mol P_{2}O_{5}}{5 mol O_{2}} = 3.40 mol P_{2}O_{5} [/tex]
3.80 mol [tex] P_{2}O_{5} [/tex] is formed from P (limiting reactant):
Moles of P = [tex] 3.80 mol P_{2}O_{5} * \frac{4 mol P\pi}{2 mol P_{2}O_{5}} = 7.6 mol P [/tex]
3.40 mol [tex] P_{2}O_{5} [/tex] is produced when Oxygen is limiting:
Moles of [tex] O_{2} [/tex] = [tex] 3.40 mol P_{2}O_{5} * \frac{5 mol O_{2}}{2 mol P_{2}O_{5}} = 8.5 mol O_{2} [/tex]
So we have 7.6 mol P and 8.5 mol O2.
Calculating the moles of P2O5 formed from the given moles of P and O2:
Moles of phosphorus pentoxide from P = [tex] 7.60 mol P * \frac{2 mol P_{2}O_{5}}{4 mol P} [/tex]
So the moles of [tex] P_{2}O_{5} [/tex] produced from P are
= [tex] 3.80 mol P_{2}O_{5} [/tex]
Moles of phosphorus pentoxide formed from O2 = [tex] 8.5 mol O_{2} * \frac{2 mol P_{2}O_{5}}{5 mol O_{2}} = 3.40 mol P_{2}O_{5} [/tex]
O2 produced the least amount of the product so oxygen would be the limiting reactant.
Moles of [tex] P_{2}O_{5} [/tex] produced will be 3.40 mol
