To obtain phosphorus oxide (5), 16 g of oxygen and 15.5 g of phosphorus were used. Determine what substance is taken

To obtain phosphorus oxide (5), 16 g of oxygen and 15.5 g of phosphorus were used. Determine what substance is taken in excess and what mass of phosphorus oxide (5) is obtained in this reaction.

The synthesis reaction of pentavalent phosphorus oxide is described by the following chemical reaction equation:

4P + 5O2 = 2P2O5;

4 phosphorus atoms interact with 5 oxygen molecules. During the reaction, 2 molecules of pentavalent phosphorus oxide are synthesized.

Let’s calculate the chemical amount of a substance contained in phosphorus weighing 15.5 grams.

M P = 31 grams / mol; N P = 15.5 / 31 = 0.5 mol;

Let’s calculate the chemical amount of a substance in oxygen with a mass of 16 grams.

M O2 = 16 x 2 = 32 grams / mol; N O2 = 16/32 = 0.5 mol;

With 0.5 mol of oxygen, they will react with 0.4 mol of phosphorus. Thus, phosphorus is taken in excess.

The weight of pentavalent phosphorus oxide will be:

M P2O5 = 31 x 2 + 16 x 5 = 142 grams / mol;

m P2O5 = 0.4 / 2 x 142 = 28.4 grams;