Identify the correct mole-mole factor needed to find moles of O2 that needed to react with moles of P for the chemical equation, 4P(s)+5O2(g)→2P2O5(s) .

Question

a. 1/2 moles of 02 per mole of P

b. 3/4 moles of 02 per mole of P

c. 5/4 moles of 02 per mole of P

d. 1 moles of 02 per mole of P

Answer 1

Based on the balanced equation, you need 5 mol of O2 for every 4 mol of P.

1 mol of P x (5 mol of O2 / 4 mol of P) = 5/4 mol of O2

Answer 2

5 mols O2 react with 4 moles of P

mole ratio of O2 to P is 5 : 4

Converting this to per mole of P, we have 5/4 O2 : 4/4 P

So, correct answer is (c) 5/4 moles of O2 per mole of P