Calculate ΔH for the following reaction at 298 K:
Fe₂O₃(s) + CO(g) → 2FeO(s) + CO₂(g)
from the following thermochemical equations:
(i) 3Fe₂O₃(s) + CO(g) → 2Fe₃O₄(s) + CO₂(g); ΔH = -46.0 kJ
(ii) Fe₃O₄(s) + CO(g) → 3FeO(s) + CO₂(g); ΔH = +41.0 kJ

Question

Calculate ΔH for the following reaction at 298 K:

Fe₂O₃(s) + CO(g) → 2FeO(s) + CO₂(g)

from the following thermochemical equations:

(i) 3Fe₂O₃(s) + CO(g) → 2Fe₃O₄(s) + CO₂(g); ΔH = -46.0 kJ

(ii) Fe₃O₄(s) + CO(g) → 3FeO(s) + CO₂(g); ΔH = +41.0 kJ

TestHub · Accepted Answer

Three times the target: 3Fe 2 O 3 + 3CO → 6FeO + 3CO 2 . This equals (i) + 2(ii): the Fe 3 O 4 cancels. 3ΔH = -46.0 + 2(41.0) = +36.0 kJ, so ΔH = +12.0 kJ. This is option (d).

Chemistry - Thermochemistry Question with Solution | TestHub

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