To calculate the enthalpy of oxidation for the reaction of 2 moles of magnesium with 1 mole of oxygen gas, we can use the following balanced chemical equation:2 Mg s + O g 2 MgO s Next, we can use the standard enthalpy of formation Hf of MgO, which is given as -601.8 kJ/mol. The standard enthalpy of formation for elements in their standard states Mg and O is zero.The enthalpy change for the reaction Hrxn can be calculated using the following equation:Hrxn = [Hf products ] - [Hf reactants ]For this reaction, we have:Hrxn = [2 Hf MgO ] - [2 Hf Mg + Hf O ]Since the standard enthalpy of formation for Mg and O is zero, the equation becomes:Hrxn = [2 -601.8 kJ/mol ] - [0]Hrxn = -1203.6 kJTherefore, the enthalpy of oxidation for the reaction of 2 moles of magnesium with 1 mole of oxygen gas under standard conditions is -1203.6 kJ.