Determine the chemical amount and masses of all substances contained in 26.2 g
Determine the chemical amount and masses of all substances contained in 26.2 g of a mixture of P2O5 and SO3, if the mass fraction of phosphorus atoms in this mixture is 23.6%
1. Let’s calculate the mass of phosphorus in the presented mixture:
m (P) = w (P) * m (mixture) = 0.236 * 26.2 = 6.1832 g;
2.Calculate the chemical amount of phosphorus:
n (P) = m (P): Ar (P) = 6.1832: 31 = 0.1995 mol;
3.Let us decompose phosphorus oxide into chemical elements:
P2O5 → 2P + 5O;
4.from the atomic ratio, we determine the amount of phosphorus oxide:
n (P2O5) = n (P): 2 = 0.1995: 2 = 0.09975 mol;
5. find the mass of P2O5 in the mixture:
m (P2O5) = n (P2O5) * M (P2O5);
M (P2O5) = 2 * 31 + 5 * 16 = 142 g / mol;
m (P2O5) = 0.09975 * 142 = 14.1645 g;
6.determine the mass of sulfur oxide and its chemical amount:
m (SO3) = m (mixture) – m (P2O5) = 26.2-14.1645 = 12.0355 g;
n (SO3) = m (SO3): M (SO3);
M (SO3) = 32 + 3 * 16 = 80 g / mol;
n (SO3) = 12.0355: 80 = 0.1504 mol.
Answer: 0.1995 mol and 14.1645 g of P2O5; 0.1504 mol and 12.0355 g SO3.