The heat produced by 4.5 moles of magnesium when burnt is 2700 kJ.
A thermochemical reaction is a reaction in which the amount of heat lost or gained is included in the reaction equation. The thermochemical reaction equation for the combustion of magnesium is shown as follows;
2 Mg(s) + O2(g) → 2 MgO(s) + 1200 kJ
From the reaction equation;
2 moles of magnesium produced 1200 kJ of heat
4.5 moles of magnesium will produce 4.5 moles × 1200 kJ/2 moles
= 2700 kJ
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