Enthalpy calculation

Question

what is the change in enthalpy when 2.3 moles of magnesium is reacted in the following equation: 2Mg(s) + O2(g) --> 2MgO(s) delta H = -1204 kJ

Answer 1

The enthalpy change for the reaction of magnesium with oxygen is about -602 kj/mole, so the quantity you gave would be for the reaction of 2 moles of magnesium.

The calculation would be -1204 kj / 2 moles Mg x 2.3 moles Mg = -1385 kj.