JEE Main 2026 (Online) 28th January Evening Shift | Thermodynamics Question 12 | Chemistry

1

JEE Main 2026 (Online) 28th January Evening Shift

MCQ (Single Correct Answer)

+4

-1

The plot of $\log_{10} K$ vs $\frac{1}{T}$ gives a straight line. The intercept and slope respectively are (where K is equilibrium constant).

A

$-\frac{\Delta S^{\circ} R}{2.303}, \frac{\Delta H^{\circ} R}{2.303}$

B

$-\frac{\Delta H^{\circ}}{2.303R}, \frac{\Delta S^{\circ}}{2.303R}$

C

$\frac{\Delta S^{\circ}}{2.303R}, -\frac{\Delta H^{\circ}}{2.303R}$

D

$\frac{2.303R}{\Delta H^{\circ}}, \frac{2.303R}{\Delta S^{\circ}}$

2

JEE Main 2026 (Online) 28th January Morning Shift

MCQ (Single Correct Answer)

+4

-1

$20.0 \mathrm{dm}^3$ of an ideal gas ' X ' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa . Which of the following option is correct?

(Given: $\log 2=0.3010$ and $\log 5=0.6989$ )

A

$\mathrm{w}=-9.1 \mathrm{~kJ}, \Delta \mathrm{U}=0, \Delta \mathrm{H}=0, \mathrm{q}=9.1 \mathrm{~kJ}$

B

$\mathrm{w}=9.1 \mathrm{~J}, \Delta \mathrm{U}=9.1 \mathrm{~J}, \Delta \mathrm{H}=0 ; \mathrm{q}=0$

C

$\mathrm{w}=-3.9 \mathrm{~kJ}, \Delta \mathrm{U}=0, \Delta \mathrm{H}=0 ; \mathrm{q}=3.9 \mathrm{~kJ}$

D

$\mathrm{w}=+4.1 \mathrm{~kJ}, \Delta \mathrm{U}=0, \Delta \mathrm{H}=0 ; \mathrm{q}=-4.1 \mathrm{~kJ}$

3

JEE Main 2026 (Online) 24th January Evening Shift

MCQ (Single Correct Answer)

+4

-1

The heat of atomisation of methane and ethane are ' x ' $\mathrm{kJ} \mathrm{mol}^{-1}$ and ' y ' $\mathrm{kJ} \mathrm{mol}^{-1}$ respectively. The longest wavelength ( $\lambda$ ) of light capable of breaking the $\mathrm{C}-\mathrm{C}$ bond can be expressed in SI unit as :

A

$\frac{\mathrm{N}_{\mathrm{A}} \mathrm{hc}}{250(y-6 x)}$

B

$\mathrm{N}_{\mathrm{A}} \mathrm{hc}\left(y-\frac{6 x}{4}\right)^{-1}$

C

$\frac{\mathrm{hc}}{1000}\left(\frac{y-6 x}{4}\right)^{-1}$

D

$\frac{\mathrm{N}_{\mathrm{A}} \mathrm{hc}}{250(4 y-6 x)}$

4

JEE Main 2026 (Online) 24th January Morning Shift

MCQ (Single Correct Answer)

+4

-1

$$ \text { Match the LIST-I with LIST-II } $$

List-I Isothermal process for ideal gas system		List-II Work done ( )
A.	Reversible expansion	I.
B.	Free expansion	II.
C.	Irreversible expansion	III.
D.	Irreversible compression	IV.

Choose the correct answer from the options given below:

A

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

B

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

C

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

D

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

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