Explanation:
Equation of the reaction:
P₄ + 5O₂ → 2P₂O₅.
Given:
Mass of P₄ = 161 g.
Molar mass = 124 g/mol
Number of moles of P₄ = mass/molar mass
n(P₄) = 161 g ÷ 124 g/mol.
= 1.3 mol.
Mass of O₂ = 176 g.
Molar mass of O₂ = 2 ×16
= 32 g/mol
Number of moles = 176 g ÷ 32 g/mol.
= 5.5 moles
Calculating the limiting reactant,
5.5 mol of O2/5 mole of O2 × 1 mole of P₄
= 2.75 moles of P₄ (> 1.3 moles)
P₄ is the limiting reagent.
By stoichiometry, 1 mole of P₄ gives 2 mole of P₂O₅
Therefore, number of moles of P₂O₅ = 2 × 1.3
= 2.6 moles of P₂O₅ was formed.
