Given the reaction 2Mg + O2 = 2MgO, if you have 2 moles of both materials how much MgO would be produced?

2Mg + O₂ → 2MgO
2 moles of Mg reacts with 1 mole of O₂ to give 2 moles of MgO.

If there are 2 moles of Mg and 2 moles of O₂, there is 1 mole of excess and 2 moles of Mg completely reacts.

When 2 moles of Mg reacts, no.. of moles of Mg produced = 2 mol

Molar mass of MgO = (24.3 + 16.0) g/mol = 40.3 g/mol
Mass of MgO produced = (2 mol) × (40.3 g/mol) = 80.6 g