How many moles of phosphorus oxide are formed if oxygen with a volume of 11.2 liters reacted with phosphorus?

Let’s execute the solution:

According to the condition of the problem, we will write the data:
4P + 5O2 = 2P2O5 – compounds, phosphorus oxide was formed (5);

Calculations according to the formulas of substances:
M (P2O5) = 141.8 g / mol;

M (O2) = 32 g / mol.

Determine the amount of the original substance and the product, make up the proportion:
1 mol of gas at normal level – 22.4 liters;

X mol (O2) – 11.2 liters from here, X mol (O2) = 1 * 11.2 / 22.4 = 0.5 mol.

0.5 mol (O2) – X mol (P2O5);

-5 mol – 2 mol hence, X mol (P2O5) = 0.5 * 2/5 = 0.2 mol.

Answer: received phosphoric anhydride amount of 0.2 mol.