What is the mass of magnesium reacted with 16g. oxygen? How much oxygen is required to oxidize 2 mol of magnesium?

Decision:
1. Let’s compose the reaction equation:
2Mg + O2 = 2MgO – magnesium oxidation reaction, magnesium oxide was obtained;
2. Let’s make calculations using the formulas:
M (Mg) = 24.3 g / mol;
M (O2) = 16 * 2 = 32 g / mol;
3. Let’s calculate the number of moles of magnesium, if the mass is known:
Y (O2) = m / M = 16/32 = 0.5 mol;
4. Let’s make a proportion according to the reaction equation:
X mol (Mg) – 0.5 mol (O2);
-2 mol -1 mol hence, X mol (Mg) = 2 * 0.5 / 1 = 1 mol;
5. Determine the mass of magnesium by the formula:
M (Mg) = Y (Mg) * M (Mg) = 0.1 * 24.3 = 2.43 g.
5. Determine the volume of oxygen:
2 mol (Mg) – X mol (O2);
-2 mol – -1 mol hence, X mol (O2) = 2 * 1/2 = 1 mol;
6. Let’s calculate the volume of О2 according to Avogadro’s law:
V (O2) = 1 * 22.4 = 22.4 liters.
Answer: the mass of magnesium is 2.43 g, the volume of oxygen is 22.4 liters.