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Heat of Reaction

Enthalpies of...

Question

Enthalpies of formation of $C O_{(g)}, C O_{2 (g)}, N_{2} O_{(g)}$ and $N_{2} O_{4 (g)} a r e - 110 k J m o l^{- 1}, - 393 k J m o l^{- 1}, 81 k J m o l^{- 1}$ and $9.7 k J m o l^{- 1}$ respectively. Find the value of $Δ_{r} H$ for the reaction:
$N_{2} O_{4 (g)} + 3 C O_{(g)} \to N_{2} O_{(g)} + 3 C O_{2 (g)}$

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Solution

$Δ_{r} H$ for a reaction is defined as the difference between $Δ_{f} H$ value of products and $Δ_{f} H$ value of reactants.

$Δ_{r} H = \sum Δ_{f} H (p r o d u c t s) - \sum Δ_{f} H (r e c t a n t s)$
For the given reaction,
$N_{2} O_{4 (g)} + 3 C O_{(g)} \to N_{2} O_{(g)} + 3 C O_{2 (g)} Δ_{r} H = [{Δ_{f} H (N_{2} O) + 3 Δ_{f} H (C O_{2})} - {Δ_{f} H (N_{2} O_{4}) + 3 Δ_{f} H (C O)}]$
Substituting the values of $Δ_{f} H$ for $N_{2} O, C O_{2}, N_{2} O_{4}$ , and CO from the question, we get:
$Δ_{f} H = [{81 k J m o l^{- 1} + 3 (- 393) k J m o l^{- 1}} - {9.7 k J m o l^{- 1} + 3 (- 110) k J m o l^{- 1}}] Δ_{r} H = - 777.7 k J m o l^{- 1}$
Hence, the value of $Δ_{r} H$ for the reaction is $- 777.7 k J m o l^{- 1}$

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Similar questions

Enthalpies of formation of CO₍_g_),CO₂₍_g_),N₂O₍_g₎and N₂O₄₍_g₎are –110 kJ mol^–1, – 393 kJ mol^–1, 81 kJ mol^–1 and 9.7 kJ mol^–1 respectively. Find the value of Δ_rH for the reaction:

N₂O₄₍_g₎ + 3CO₍_g₎ N₂O₍_g₎ + 3CO₂₍_g₎

Q. Enthalpies of formation of CO(g),

C O_{2} (g)

N_{2} O (g)

and

N_{2} O_{4} (g)

are

- 110, - 393.81

and

9.7 k J

m o l^{- 1}

respectively. Find the value of

△_{r} H

for the reaction :

N_{2} O_{4} (g) + 3 C O (g) \to N_{2} O (g) + 3 C O_{2} (g)

Q. Enthalpies of formation

C O (g), C O_{2} (g), N_{2} O (g)

and

N_{2} O_{4} (g)

are

- 110, - 393, 81

and

9.7

KJ/mol respectively. Find the value of

Δ

H for the reaction.

N_{2} O_{4} (g) + 3 C O \to N_{2} O (g) + 3 C O_{2} (g)

Q. The enthalpy of formation of

C O_{(g)}, C O_{2 (g)}, N_{2} O_{(g)}

and

N_{2} O_{4 (g)}

- 110, - 393, + 811

and

10 k J / m o l

respectively. For the reaction,

N_{2} O_{4 (g)} + 3 C O_{(g)} \to N_{2} O_{(g)} + 3 C O_{2 (g)} \cdot △ H_{r} (k J / m o l)

Q. What is the change in oxidation number of carbon in the following reaction?

N_{2} O_{4} (g) + 3 C O (g) \to N_{2} O (g) + 3 C O_{2} (g)

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Heat of Reaction

Standard XII Chemistry

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Enthalpies of formation of CO(g),CO2(g),N2O(g) and N2O4(g)are–11 0kJ mol−1,–393 kJ mol−1,81 kJ mol–1 and 9.7 kJ mol−1 respectively. Find the value of ΔrH for the reaction: N2O4(g)+3CO(g)→N2O(g)+3CO2(g)