Question

Some hot packs uses the reaction iron metal with oxygen
from air to generate heat:

4 Fe(s) + 3 O2(g) => 2 Fe2O3(s), ΔH = -1.65 MJ

How much heat (in kJ) will be produced if 57.61 g of iron is used in this reaction?
{Enter the magnitude of the heat as a positive value}

Answer 1

-1.65 MJ = -1650 kJ.
1 mol Fe = 55.85
4 mols Fe as in the equation = 4(55.85) = 223.4 g.
So the heat emitted = 1650 kJ x (57.61 g/223.4 g) = ? kJ