For the reaction :

N₂ + 3H₂ $\rightleftharpoons$ 2NH₃ ; $\mathrm{∆}$H = ?

• $∆$E + 2RT

• $∆$E - 2RT

• $∆$E + RT

• $∆$E - RT

Which thermodynamic parameter is not a state function?

• q at constant pressure

• q at constant volume

• W at adiabatic

• W at isothermal

Assertion: For an isolated system, q is zero.

Reason : In an isolated system, change in U and V is zero.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Entropy of system increases for a spontaneous reaction.

Reason : Enthalpy of reaction always decreases for spontaneous reaction.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Catalyst changes Gibbs free energy of system.

Reason : Catalyst changes pre-exponential factor of a chemical reaction.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

76.

Assertion : A process is called adiabatic if the system does not exchange heat with the surroundings.

Reason : It does not not involve increase or decrease in temperature of the system.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Heat of combustion of C and CO are -394 and -285 kJ respectively , so heat of formation of CO in kJ/mol is :

• - 218

• - 109

• + 109

• + 218

For endothermic reaction :

• E_a > E_a^'

• E_a = E_a^'

• E_a < E_a^'

• None of these

The enthalpy of formation of CO_(g), CO_2(g), N₂O_(g), and N₂O_4(g) is -110, -393, +811 and 10 kJ/mol respectively. For the reaction, N₂O₄ + 3CO_(g) $\to$ N₂O_(g)+ 3CO_2(g); $∆$H_r (kJ/mol) is

• -212

• +212

• +48

• -48

The difference between heat of reaction at constant pressure and constant volume of the reaction :

2C₆H₆ (l) + 15O₂ (g) $\to$ 12CO₂ + 6H₂O (l)

at 25°C (in kJ) is :

• - 7.43

• 3.72

• - 3.72

• 7.43