What mass of phosphorus must be burned to obtain phosphorus oxide (v) with a mass of 7.1 g?

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

4P + 5O2 = 2P2O5;

4 phosphorus atoms interact with 5 oxygen molecules. In this case, 2 molecules of phosphorus oxide are synthesized.

Let’s calculate the chemical amount of a substance in phosphorus oxide weighing 7.1 grams.

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

N P2O5 = 7.1 / 142 = 0.05 mol;

To synthesize such an amount of oxide, it is necessary to oxidize 0.05 x 2 = 0.1 mol of phosphorus.

Let’s calculate its weight.

To do this, we multiply the amount of the substance by its molar weight.

M P = 31 grams / mol;

m P = 31 x 0.1 = 3.1 grams;