Answer:
Standard Heat of Reaction 1 = -136.2 kJ/mol
Standard Heat of Reaction 2 = -41.166 kJ/mol
Standard Heat of Reaction 3 = -136.07 kJ/mol
Standard Heat of Reaction 4 = 279.448kJ/mol
Explanation:
C₂H₄ (g) + H₂ (g) → C₂H₆ (g)
CO (g) + H₂O (g) → H₂ (g) + CO₂ (g)
3NO₂ (g) + H₂O (l) → 2HNO₃ (aq) + NO (g)
Cr₂O₃ (s) + 3CO (g) → 2Cr (s) + 3CO₂ (g)
The required standard heat of formation for each of the reactants and product above, as obtained from literature is listed below.
C₂H₄ (g), 52.5 kJ/mol
H₂ (g), 0 kJ/mol
C₂H₆ (g), -83.7 kJ/mol
CO (g), -110.525 kJ/mol
H₂O (g), -241.818 kJ/mol
H₂ (g), 0 kJ/mol
CO₂ (g), -393.509 kJ/mol
NO₂ (g), 33.2 kJ/mol
H₂O (l), -285.8 kJ/mol
HNO₃ (aq), -206.28 kJ/mol
NO (g), 90.29 kJ/mol
Cr₂O₃ (s), -1128.4 kJ/mol
CO (g), -110.525 kJ/mol
Cr (s), 0 kJ/mol
CO₂ (g), -393.509 kJ/mol
Note that
ΔH∘(rxn) = ΔH∘(products) - ΔH∘(reactants)
C₂H₄ (g) + H₂ (g) → C₂H₆ (g)
ΔH∘(rxn) = ΔH∘(products) - ΔH∘(reactants)
ΔH∘(products) = (1×-83.7) = -83.7 kJ/mol
ΔH∘(reactants) = (1×52.5) + (1×0) = 52.5 kJ/mol
ΔH∘(rxn) = -83.7 - 52.5 = -136.2 kJ/mol
CO (g) + H₂O (g) → H₂ (g) + CO₂ (g)
ΔH∘(rxn) = ΔH∘(products) - ΔH∘(reactants)
ΔH∘(products) = (1×0) + (1×-393.509) = -393.509 kJ/mol
ΔH∘(reactants) = (1×-110.525) + (1×-241.818) = -352.343 kJ/mol
ΔH∘(rxn) = -393.509 - (-352.343) = -41.166 kJ/mol
3NO₂ (g) + H₂O (l) → 2HNO₃ (aq) + NO (g)
ΔH∘(rxn) = ΔH∘(products) - ΔH∘(reactants)
ΔH∘(products) = (2×-206.28) + (1×90.29) = -322.27 kJ/mol
ΔH∘(reactants) = (3×33.2) + (1×-285.8) = -186.2 kJ/mol
ΔH∘(rxn) = -322.27 - (-186.2) = -136.07 kJ/mol
Cr₂O₃ (s) + 3CO (g) → 2Cr (s) + 3CO₂ (g)
ΔH∘(rxn) = ΔH∘(products) - ΔH∘(reactants)
ΔH∘(products) = (2×0) + (3×-393.509) = -1,180.527 kJ/mol
ΔH∘(reactants) = (1×-1128.4) + (3×-110.525) = -1,459.975 kJ/mol
ΔH∘(rxn) = -1,180.527 - (-1,459.975) = 279.448 kJ/mol
Hope this Helps!!!
is the pressure of the gas,
is the volume of the gas,
is the number of moles of particles in this gas,
is the ideal gas constant, and
is the absolute temperature of the gas (in degrees Kelvins.)
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