JEE Main 2025 Question Paper (23-Jan-2025) (Shift 2)

Question 1

The effect of temperature on spontaneity of reactions are represented as: $ \begin{array}{ccccc} & \mathbf{\Delta H} & \mathbf{\Delta S} & \mathbf{Temperature} & \mathbf{Spontaneity} \ \left(Aight) & + & - & 	ext{any } T & 	ext{Non spontaneous} \ \left(Bight) & + & + & 	ext{low } T & 	ext{spontaneous} \ \left(Cight) & - & - & 	ext{low } T & 	ext{Non spontaneous} \ \left(Dight) & - & + & 	ext{any } T & 	ext{spontaneous} \end{array} $

Accepted Answer

(B) and (C) only

Answer

(B) and (D) only

Answer

(A) and (D) only

Answer

(A) and (C) only

Question 2

Standard electrode potentials for a few half cells are mentioned below: $ E^\circ_{\mathrm{Cu^{2+}/Cu}} = 0.34\,V, \quad E^\circ_{\mathrm{Zn^{2+}/Zn}} = -0.76\,V $ $ E^\circ_{\mathrm{Ag^{+}/Ag}} = 0.80\,V, \quad E^\circ_{\mathrm{Mg^{2+}/Mg}} = -2.37\,V $ Which one of the following cells gives the most negative value of $\Delta G^\circ$?

Accepted Answer

$ Zn \mid Zn^{2+}  (1M)  \|  Ag^{+} (1M) \mid Ag $

Answer

$ Zn \mid Zn^{2+}  (1M)  \|  Mg^{2+}  (1M) \mid Mg $

Answer

$Ag|Ag^{2+}  (1M)  ||   Mg^{2+} (1M)  |  Mg$

Answer

$\mathrm{Cu} \mid \mathrm{Cu}^{2+} (1\,\mathrm{M}) \|  \mathrm{Ag}^{+} (1\,\mathrm{M}) \mid \mathrm{Ag}$

Question 3

The $\alpha$-helix and $\beta$-pleated sheet structures of proteins are associated with its:

Accepted Answer

secondary structure

Answer

quaternary structure

Answer

primary structure

Answer

tertiary structure

Question 4

Given below are two statements:  Consider the following reactionStatement (I): In the case of formaldehyde K is about 2280, due to small substituents, hydration is faster.   Statement (II) : In the case of trichlorodue to I effect of - Cl.In the light of the above statements, choose thecorrect answer from the options given below:

Accepted Answer

Both Statement I and Statement II are true

Answer

Statement I true but Statement II is false

Answer

Statement I is false but Statement II is true

Answer

Both Statement I and Statement II are false

Question 5

Consider the reaction$ X_2Y(g) \rightleftharpoons X_2(g) + \frac{1}{2} Y_2(g) $The equation representing the correct relationship between the degree of dissociation $\left(x\right)$ of $X_2Y(g)$ with its equilibrium constant $K_p$ is $\_\_\_\_\_\_\_\_\_\_$. Assume $x$ to be very very small.

Accepted Answer

$ x = \sqrt[3]{\frac{2K p^{2}}{p}} $

Answer

$ x = \sqrt[3]{\frac{2Kp}{p}} $

Answer

$x = \sqrt[3]{\frac{Kp}{2p}}$

Answer

$ x = \sqrt[3]{\frac{K_p}{p}} $