Calculate the mass of the reaction product formed during the combustion of 1.5 mol of phosphorus in oxygen.

To solve this problem, we write down given: v (P) = 1.5 mol. Phosphorus burns in oxygen;
Find: the mass of the formed oxide;
Decision:
Let’s write the reaction equation:
P + O2 = P2O5
Let’s arrange the coefficients;
4P + 5O2 = 2P2O5
We write 1.5 mol over phosphorus, and 4 mol under phosphorus;
Calculate the molecular weight of phosphorus (V) oxide
M (P2O5) = 31 * 2 + 16 * 5 = 142 g / mol.
Since phosphorus (V) oxide formed 2 mol, you need 2 mol * 142 g / mol = 284 g;
Above phosphorus (V) oxide we write x g, and under phosphorus (V) oxide, a molar mass equal to 284 g4
Let’s compose and solve the proportion:
x = 1.5 * 284/4 = 106.5 g
Answer: 106.5 g.