The reaction given below shows the enthalpy change for the chemical reactants between N2- O2- NO and NO2N2g-O2g- 2NOg - H - -110 kJ-mol2NOg-O2g- 2NO2g - H - -200 kJ-molThe correct statement among the following is-are-

Given reactions are, N_2(g)+O_2(g)→ 2NO(g) Δ H = 110 kJ/mol ··· (1) 2NO(g)+O_2(g)→ 2NO_2(g) Δ H = 200 kJ/mol ··· (1) ∴ Adding equations (1) and (2), N_2(g)+ ...

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Byju's Answer

Standard XII

Chemistry

Gibb's Energy and Nernst Equation

The reaction ...

Question

The reaction given below shows the enthalpy change for the chemical reactants between $N_{2}$ , $O_{2}$ , $N O$ and $N O_{2}$
$N_{2} (g) + O_{2} (g) \to 2 N O (g) Δ H = - 110 kJ/mol$
$2 N O (g) + O_{2} (g) \to 2 N O_{2} (g) Δ H = - 200 kJ/mol$
The correct statement among the following is/are:

The standard heat of formation of

N O_{2}

- 90 kJ/mol

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The oxidation reaction from

N_{2}

N O_{2}

is exothermic

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The standard heat of formation of

N O

- 55 kJ/mol

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The oxidation reaction of

N O

N O_{2}

is endothermic

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Solution

The correct option is C The standard heat of formation of $N O$ is $- 55 kJ/mol$
Given reactions are,
$N_{2} (g) + O_{2} (g) \to 2 N O (g) Δ H = - 110 kJ/mol \cdot \cdot \cdot (1)$
$2 N O (g) + O_{2} (g) \to 2 N O_{2} (g) Δ H = - 200 kJ/mol \cdot \cdot \cdot (1)$
$∴$ Adding equations $(1)$ and $(2)$ ,
$N_{2} (g) + 2 O_{2} (g) \to 2 N O_{2} Δ H = - 310 kJ/mol$
So the standard heat of formation of $N O_{2}$ = $\frac{- 310}{2} kJ/mol = - 155 kJ/mol$
Thus in the oxidation reaction from $N_{2}$ to $N O_{2}$ $310 kJ/mol$ heat evolves. Thus it is exothermic.
From the reaction $(1)$ ,
$\frac{1}{2} N_{2} (g) + \frac{1}{2} O_{2} (g) \to N O (g) Δ H = - 55 kJ/mol \cdot \cdot \cdot (1)$
So the standard heat of formation of $N O$ is $- 55 kJ/mol$
From equation (2), the heat evolved in the oxidation reaction of $N O$ to $N O_{2}$ is $- 200 kJ/mol$ .
So it is exothermic.

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Similar questions

Q. For the gas phase reaction (1) shown below, which of the following statement is true for reaction (2)?
1.

2 N O ⇌ N_{2} + O_{2}, Δ H = - 43.5 k C a l

N_{2} (g) + O_{2} (g) ⇌ 2 N O (g)

Q. Given :

C (g r a p h i t e) + \frac{1}{2} O_{2} \to C O Δ H_{1} = - 110.5 k J / m o l

C O + \frac{1}{2} O_{2} \to C O_{2} Δ H = - 283.2 k J / m o l

The heat of reaction (in

k J / m o l

) for the following reaction is:

C (g r a p h i t e) + O_{2} \to C O_{2} Δ H = ?

Q. Following are the thermochemical reactions:

C

(graphite)

+ \frac{1}{2} O_{2} \to C O; Δ H = - 110.5

kJ/mol

C O + \frac{1}{2} O_{2} \to C O_{2}; Δ H = - 283.2

kJ/mol

The heat of reaction (in kJ/mol) for the following reaction is:

C (graphite) + O_{2} \to C O_{2}

\begin{matrix} List - I & List - II (I) Dissociation of N_{2} O_{4} (g) : & (P) Increases with N_{2} O_{4} (g) ⇌ 2 N O_{2} (g); & temperature Δ H = + 57.0 k J (II) Oxidation of N H_{3} (g) : & (Q) Decreases with 4 N H_{3} (g) + 5 O_{2} ⇌ 4 N O (g) + 6 H_{2} O (g); & pressure Δ H = - 900.0 k J (III) Oxidation of nitrogen: & (R) Increases with N_{2} (g) + O_{2} (g) ⇌ 2 N O (g); & addition of inert Δ H = + 180.0 k J & gas at constant pressure (IV) Formation of N O_{2} (g) : & (S) Decreases with N O (g) + O_{3} (g) ⇌ N O_{2} (g) + O_{2} (g); & temperature Δ H = - 200.0 k J (T) K_{p} = K_{c} (U) K_{p} = K_{c} (R T)^{1} \end{matrix}

Which of the following options has the correct combination considering List-I and List-II?

Q. Which of the following is not true for the equilibrium reaction?

N_{2} (h) + O_{2} (g) ⇌ 2 N O (g); Δ H = 180

m o l^{- 1}

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The reaction given below shows the enthalpy change for the chemical reactants between N2, O2, NO and NO2 N2(g)+O2(g)→2NO(g) ΔH=−110 kJ/mol 2NO(g)+O2(g)→2NO2(g) ΔH=−200 kJ/mol The correct statement among the following is/are:

The reaction given below shows the enthalpy change for the chemical reactants between $N_{2}$ , $O_{2}$ , $N O$ and $N O_{2}$
$N_{2} (g) + O_{2} (g) \to 2 N O (g) Δ H = - 110 kJ/mol$
$2 N O (g) + O_{2} (g) \to 2 N O_{2} (g) Δ H = - 200 kJ/mol$
The correct statement among the following is/are: