How many kilojoules of heat will be released when exactly 1 mole of iron, Fe, is burned to form Fe2O3 at standard state condaition?

412.1kJ

Explanation:

For the reaction, from the question -

4Fe (s) + 3O₂ (g) → 2Fe₂O₃ (s)

Δ Hrxn = Δ H°f (products) - Δ H°f (reactants)

In case the compound is in its standard state, enthalphy of formation is zero

Hence,

for the above reaction,

ΔHrxn = (2 * Δ H° (Fe₂O₃)) - [ (4 * Δ H° Fe) + (3 * Δ H° O₂) ]

The value for Δ H° (Fe₂O₃) = - 824.2kJ/mol

Δ H° Fe = 0

Δ H° O₂ = 0

Putting in the above equation,

ΔH rxn = (2 * Δ H° (Fe₂O₃)) - 0

ΔHrxn = 2 * - 824.2 kJ / mol = - 1648.4 kJ/mol

- 1648.4 kJ/mol, this much heat is released by the buring of 4 mol of Fe.

Hence,

for 1 mol of Fe,

- 1648.4 kJ/mol / 4 = 412.1kJ