JEE Main 2025 (Online) 24th January Morning Shift | Thermodynamics Question 9 | Chemistry

1

JEE Main 2025 (Online) 24th January Morning Shift

MCQ (Single Correct Answer)

+4

-1

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option.

A

Both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are (-ve)

B

$\Delta \mathrm{H}$ is $(+\mathrm{ve})$ but $\Delta \mathrm{S}$ is (-ve)

C

$\Delta \mathrm{H}$ is $(-\mathrm{ve})$ but $\Delta \mathrm{S}$ is (+ve)

D

Both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are (+ve)

2

JEE Main 2025 (Online) 23rd January Evening Shift

MCQ (Single Correct Answer)

+4

-1

The effect of temperature on spontaneity of reactions are represented as :

	$\Delta$H	$\Delta$S	Temperature	Spontaneity
(A)	$+$	$-$	any T	Non spontaneous
(B)	$+$	$+$	low T	spontaneous
(C)	$-$	$-$	low T	Non spontaneous
(D)	$-$	$+$	any T	spontaneous

The incorrect combinations are :

A

(A) and (C) only

B

(B) and (D) only

C

(A) and (D) only

D

(B) and (C) only

3

JEE Main 2025 (Online) 23rd January Morning Shift

MCQ (Single Correct Answer)

+4

-1

Ice at $-5^{\circ} \mathrm{C}$ is heated to become vapor with temperature of $110^{\circ} \mathrm{C}$ at atmospheric pressure. The entropy change associated with this process can be obtained from

A

$\int_{268 \mathrm{~K}}^{273 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\mathrm{m}} \text {, fusion }}{\mathrm{T}_{\mathrm{f}}}+\frac{\Delta \mathrm{H}_{\mathrm{m}, \text { vaporisation }}}{\mathrm{T}_{\mathrm{b}}}+\int_{273 \mathrm{~K}}^{373 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}+\int_{373 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}$

B

$\int_{268 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\text {melting }}}{273}+\frac{\Delta \mathrm{H}_{\text {boiling }}}{373}$

C

$\int_{268 \mathrm{~K}}^{383 \mathrm{~K}} \mathrm{C}_{\mathrm{p}} \mathrm{dT}+\frac{\mathrm{q}_{\text {rev }}}{\mathrm{T}}$

D

$\int_{268 \mathrm{~K}}^{273 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{m}}}{\mathrm{T}} \mathrm{dT}+\frac{\Delta \mathrm{H}_{\mathrm{m}}, \text { fusion }}{\mathrm{T}_{\mathrm{f}}}+\frac{\Delta \mathrm{H}_{\mathrm{m}, \text { vaporisation }}^{373 \mathrm{~K}}}{\mathrm{~T}_{\mathrm{b}}}+\int_{273 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}}{T}+\int_{373 \mathrm{~K}}^{383 \mathrm{~K}} \frac{\mathrm{C}_{\mathrm{p}, \mathrm{m}} \mathrm{dT}}{\mathrm{T}}$

4

JEE Main 2025 (Online) 22nd January Evening Shift

MCQ (Single Correct Answer)

+4

-1

Match List - I with List - II.

	List - I (Partial Derivatives)		List - II (Thermodynamic Quantity)
(A)	$\left(\frac{\partial \mathrm{G}}{\partial \mathrm{T}}\right)_{\mathrm{P}}$	(I)	Cp
(B)	$\left(\frac{\partial \mathrm{H}}{\partial \mathrm{T}}\right)_{\mathrm{P}}$	(II)	$-$S
(C)	$\left(\frac{\partial \mathrm{G}}{\partial \mathrm{P}}\right)_{\mathrm{T}}$	(III)	Cv
(D)	$\left(\frac{\partial \mathrm{U}}{\partial \mathrm{T}}\right)_{\mathrm{V}}$	(IV)	V

Choose the correct answer from the options given below :

A

(A)-(I), (B)-(II), (C)-(IV), (D)-(III)

B

(A)-(II), (B)-(III), (C)-(I), (D)-(IV)

C

(A)-(II), (B)-(I), (C)-(IV), (D)-(III)

D

(A)-(II), (B)-(I), (C)-(III), (D)-(IV)