Answer:
394.76g
Explanation:
Given parameters:
Mass of Phosphorus = 172.1g
Unknown:
Mass of P₂O₅ = ?
Solution:
We should work from the known specie to the unknown in this problem. The limiting reactant is the reactant in short supply and it determines the extent of the reaction. This is the given phosphorus.
Oxygen is in the excess.
The balanced reaction equation:
4P + 5O₂ → 2P₂O₅
let us find the number of moles of phosphorus first,
Number of moles of phosphorus = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of phosphorus = 31g/mole
Number of moles = [tex]\frac{172.1}{31}[/tex] = 5.55mole
4 moles of phosphorus gives 2 moles of P₂O₅
5.55 mole of P will produce [tex]\frac{5.55 x 2}{4}[/tex] = 2.78moles
Mass of P₂O₅ = number of moles x molar mass
Molar mass of P₂O₅ = (31 x 2) + (16 x 5) = 142g/mole
Mass of P₂O₅ = 2.78moles x 142g/mole = 394.76g
