chemistry question

Question

Consider the reaction.

The decomposition of 81.0 g of Fe2O3 results in:

1. the release of 418 kJ of heat
2. the release of 33400 kJ of heat
3. the absorption of 33400 kJ of heat
4. the absorption of 418 kJ of heat
5. the absorption of 209 kJ of heat
6. the release of 209 kJ of heat

Answer 1

∆H is positive indicating that during the reaction heat is ABSORBED

moles Fe2O3 decomposed = 81.0 g Fe2O3 x 1 mol/159.69 g = 0.51 moles

824.2 kJ/2 moles Fe2O3 x 0.51 moles = 210 kJ absorbed

Best answer is the absorption of 209 kJ of heat