Calculate the amount of substance and mass (O2) formed during the decomposition of 0.2 mol 2KMnO4 = K2MnO4 + MnO2

To solve, we write down the reaction equation:
2KMnO4 = K2MnO4 + MnO2 + O2 – the decomposition reaction of potassium permanganate occurs when heated, oxygen is released;
Let’s calculate the molar masses of substances:
M (KMnO4) = 39.1 + 54.9 + 16 * 4 = 158 g / mol;
M (O2) = 2 * 16 = 32 g / mol;
Determine the amount of moles of oxygen:
0.2 mol (KMnO4) – X mol (O2);
-2 mol                      – 1 mol from here, X mol (O2) = 0.2 * 1/2 = 0.1 mol;
We calculate the mass of oxygen by the formula:
m (O2) = Y * M = 0.1 * 32 = 3.2 g.
Answer: during the reaction, oxygen is released in an amount of 0.1 mol, the mass is 3.2 g.