Calculate the mass of higher phosphorus oxide reacted with water, if phosphoric acid was obtained

Calculate the mass of higher phosphorus oxide reacted with water, if phosphoric acid was obtained with a mass of 44 g, which is 90% of the theoretically possible.

To solve, write down the equation:
1. Р2О5 + 3Н2О = 2Н3РО4 – compounds, phosphoric acid was obtained;
2. We make calculations:
M (P2O5) = 141.8 g / mol.
M (H3PO4) = 97.9 g / mol.
m (H3PO4) = 44 * 0.90 = 39.6 g.
3. Let’s determine the quantity of the product:
Y (H3PO4) = m / M = 39.6 / 97.9 = 0.4 mol.
4. Proportion:
X mol (P2O5) – 0.4 mol (H3PO4)
-1 mol -2 mol hence, X mol (P2O5) = 1 * 0.4 / 2 = 0.2 mol.
5. Find the mass of the original substance:
m (P2O5) = Y * M = 0.2 * 141.8 = 28.36 g.
Answer: phosphorus (5) oxide weighing 28.36 g is used in the process.