The potential energy diagram for a reaction R → P is given in the figure. $∆$H ° of the reaction corresponds to the energy

• a

• b

• c

• a + b

Assertion : The increase in internal energy ($∆$E) for the vapourization of one mole of water at 1 atm and 373 K is zero.

Reason : For all isothermal processes, $∆$E = 0.

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

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

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : BaCO₃ is more soluble in HNO₃ than in plain water.

Reason : Carbonate is a weak base and reacts with the H⁺ from the strong acid, causing the barium salt to dissociate.

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

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

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : $∆$H and $∆$E are almost the same for the reaction, N_2(g) + O_2(g) → 2NO_(g)

Reason : All reactants and products are gases.

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

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

• If assertion is true but reason is false.

• If both assertion and reason are false.

685.

Which of the following is always feasible?

• $∆\mathrm{H}=\mathrm{T}∆\mathrm{S}$

• $∆\mathrm{H}(+\mathrm{ve}), \mathrm{T}∆\mathrm{S} (-\mathrm{ve}) \mathrm{and} ∆\mathrm{H} >\mathrm{T}∆\mathrm{S}$

• $∆\mathrm{H}(-\mathrm{ve}), \mathrm{T}∆\mathrm{S} (+\mathrm{ve}) \mathrm{and} ∆\mathrm{H} < \mathrm{T}∆\mathrm{S}$

• $∆\mathrm{H}(-\mathrm{ve}), \mathrm{T}∆\mathrm{S} (-\mathrm{ve}) \mathrm{and} ∆\mathrm{H} >\mathrm{T}∆\mathrm{S}.$

Given that 

$$\begin{gathered} \mathrm{C} + {\mathrm{O}}_2 \to {\mathrm{CO}}_2 ; ∆{\mathrm{H}}^{°} =-\mathrm{a} \mathrm{kJ}. \\ 2\mathrm{CO} + {\mathrm{O}}_2 \to 2{\mathrm{CO}}_2 ; ∆{\mathrm{H}}^{°} = -\mathrm{b} \mathrm{kJ}. \end{gathered}$$ 

The heat of formation of CO is 

• $\mathrm{b}-2\mathrm{a}$

• $\frac{2\mathrm{a}-\mathrm{b}}{2}$

• $\frac{\mathrm{b}-2\mathrm{a}}{2}$

• 2a-b

For the reaction, X₂Y₄ (l) → 2XY₂ (g) at 300 K, the values of $∆$U and $∆$S are 2 kcal and 20 cal K^-1 respectively. The value of $∆$G for the reaction is

• -3400 cal

• 3400 cal

• -2800 cal

• 2000 cal

Assertion: During an adiabatic process, heat energy is not exchanged between the system and its surroundings.

Reason: The temperature of a gas increases when it undergoes an adiabatic expansion.

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

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

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

Assertion: Mass and volume are extensive properties.
Reason: Mass/volume is also an extensive parameter.

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

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

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

The values of $∆\mathrm{H}$and $∆\mathrm{S}$ of a certain reaction are -400 kJ mol^-1 and -20 kJ mol^-1K^-1 respectively. The temperature below which the reaction is spontaneous, is

• 100 K

• 20°C

• 20 K

• 120°C