Question

A student tries to make diphosphorus trioxide using the reaction below. He adds exactly 20.00 grams of Phosphorus to an excess of oxygen gas. Calculate the theoretical yield of how much P2O3 will be made
P4(s) + O2(g) ——> P2O3(s)

Answer 1

Answer:

Mass = 87.952 g

Explanation:

Given data:

Mass of phosphorus = 20.0 g

Theoretical yield of P₂O₃ = ?

Solution:

Chemical equation:

P₄ + 3O₂  →  2P₂O₃

Number of moles of phosphorus:

Number of moles = mass/ molar mass

Number of moles = 20.0 g / 123.9 g/mol

Number of moles = 0.2 mol

Now we will compare the moles of phosphorus with P₂O₃.

                         P₄         :          P₂O₃

                          1           :           2

                         0.2        :         2/1×0.2 = 0.4 mol

Theoretical yield:

Mass = number of moles × molar mass

Mass = 0.4 mol  × 219.88 g/mol

Mass = 87.952 g