Calculate the volume of oxygen that is formed during the decomposition of 15 grams

Calculate the volume of oxygen that is formed during the decomposition of 15 grams of potassium oxide, potassium has 10% impurities.

Let’s execute the solution:
1. In accordance with the condition of the problem, we compose the equation:
m = 15 g; 10% impurities;
2K2O = O2 + 4K – decomposition occurs when heated, oxygen and potassium are released;
X l. – O2.
2. Let’s make calculations using the formulas:
M (K2O) = 94.2 g / mol;
M (O2) = 32 g / mol.
3. Determine the mass of the original substance without impurities and its amount:
15 (1-0.10) = 13.5 g;
Y (K2O) = m / M = 13.5 / 94.2 = 0.14 mol.
4. Proportion:
0.14 mol (K2O) – X mol (O2);
-2 mol – 1 mol from here, X mol (O2) = 0.14 * 1/2 = 0.07 mol.
5. Find the volume of O2:
V (O2) = 0.07 * 22.4 = 1.57 liters.
Answer: oxygen was obtained with a volume of 1.57 liters.