JEE MAIN - Chemistry (2025 - 29th January Evening Shift)

1

Given below are two statements :

Statement (I): On nitration of m-xylene with $\mathrm{HNO}_3, \mathrm{H}_2 \mathrm{SO}_4$ followed by oxidation, 4-nitrobenzene-1,3-dicarboxylic acid is obtained as the major product.

Statement (II) : $-\mathrm{CH}_3$ group is o/p-directing while $-\mathrm{NO}_2$ group is m-directing group.

In the light of the above statements, choose the correct answer from the options given below :

Answer
(B)
Both Statement I and Statement II are true
2

Identify the essential amino acids from below:

(A) Valine

(B) Proline

(C) Lysine

(D) Threonine

(E) Tyrosine

Choose the correct answer from the options given below:

Answer
(A)
(A), (C) and (D) only
3

Given below are two statements :

Statement (I): NaCl is added to the ice at 0°C, present in the ice cream box to prevent the melting of ice cream.

Statement (II): On addition of NaCl to ice at 0°C, there is a depression in freezing point.

In the light of the above statements, choose the correct answer from the options given below :

Answer
(C)
Both Statement I and Statement II are true
4

Given below are two statements :

Statement (I): In partition chromatography, stationary phase is thin film of liquid present in the inert support.

Statement (II): In paper chromatography, the material of paper acts as a stationary phase.

In the light of the above statements, choose the correct answer from the options given below :

Answer
(A)
Statement I is true but Statement II is false
5

0.1 M solution of KI reacts with excess of $\mathrm{H}_2 \mathrm{SO}_4$ and $\mathrm{KIO}_3$ solutions. According to equation

$$ 5 \mathrm{I}^{-}+\mathrm{IO}_3^{-}+6 \mathrm{H}^{+} \rightarrow 3 \mathrm{I}_2+3 \mathrm{H}_2 \mathrm{O} $$

Identify the correct statements :

(A) 200 mL of KI solution reacts with 0.004 mol of $\mathrm{KIO}_3$

(B) 200 mL of KI solution reacts with 0.006 mol of $\mathrm{H}_2 \mathrm{SO}_4$

(C) 0.5 L of KI solution produced 0.005 mol of $\mathrm{I}_2$

(D) Equivalent weight of $\mathrm{KIO}_3$ is equal to ( $\frac{\text { Molecular weight }}{5}$ )

Choose the correct answer from the options given below :

Answer
(D)
(A) and (D) only
6
The type of oxide formed by the element among Li, Na, Be, Mg, B and Al that has the least atomic radius is :
Answer
(D)
A2O3
7
Which one of the following reaction sequences will give an azo dye?
Answer
(C)
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Compounds Containing Nitrogen Question 13 English Option 3
8

Identify the homoleptic complexes with odd number of $d$ electrons in the central metal :

(A) $\left[\mathrm{FeO}_4\right]^{2-}$

(B) $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}$

(C) $\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NO}\right]^{2-}$

(D) $\left[\mathrm{CoCl}_4\right]^{2-}$

(E) $\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_3 \mathrm{~F}_3\right]$

Choose the correct answer from the options given below :

Answer
(C)
(B) and (D) only
9

Match List - I with List - II :

List - I (Applications) List - II (Batteries/Cell)
(A) Transistors (I) Anode - Zn/Hg; Cathode - HgO + C
(B) Hearing aids (II) Hydrogen fuel cell
(C) Inverters (III) Anode - Zn; Cathode - Carbon
(D) Apollo space ship (IV) Anode - Pb; Cathode - Pb | PbO2

Choose the correct answer from the options given below :

Answer
(A)
(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
10
Which one of the following, with HBr will give a phenol?
Answer
(A)
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Alcohols, Phenols and Ethers Question 5 English Option 1
11
The calculated spin-only magnetic moments of $K_3[Fe(OH)_6]$ and $K_4[Fe(OH)_6]$ respectively are :
Answer
(C)
5.92 and 4.90 B.M.
12

Consider the equilibrium

$$ \mathrm{CO}(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g}) \rightleftharpoons \mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{~g}) $$

If the pressure applied over the system increases by two fold at constant temperature then

(A) Concentration of reactants and products increases.

(B) Equilibrium will shift in forward direction.

(C) Equilibrium constant increases since concentration of products increases.

(D) Equilibrium constant remains unchanged as concentration of reactants and products remain same.

Choose the correct answer from the options given below :

Answer
(A)
(A) and (B) only
13
First ionisation enthalpy values of first four group 15 elements are given below. Choose the correct value for the element that is a main component of apatite family :
Answer
(D)
1012 kJ mol−1
14

For hydrogen like species, which of the following graphs provides the most appropriate representation of E vs Z plot for a constant n?

[E : Energy of the stationary state, Z : atomic number, n = principal quantum number]

Answer
(D)
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Structure of Atom Question 11 English Option 4
15

If $\quad C$ (diamond $) \rightarrow C$ (graphite) $+X \mathrm{~kJ} \mathrm{~mol}^{-1}$

C (diamond) $+\mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{CO}_2(\mathrm{~g})+\mathrm{Y} \mathrm{kJ} \mathrm{mol}{ }^{-1}$

C (graphite) $+\mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{CO}_2(\mathrm{~g})+\mathrm{Z} \mathrm{kJ} \mathrm{mol}^{-1}$

at constant temperature. Then

Answer
(B)
X = Y − Z
16

Given below are two statements :

Statement (I): It is impossible to specify simultaneously with arbitrary precision, both the linear momentum and the position of a particle.

Statement (II) : If the uncertainty in the measurement of position and uncertainty in measurement of momentum are equal for an electron, then the uncertainty in the measurement of velocity is $\geqslant \sqrt{\frac{h}{\pi}} \times \frac{1}{2 m}$.

In the light of the above statements, choose the correct answer from the options given below :

Answer
(B)
Both Statement I and Statement II are true
17
Total number of sigma (σ) _______ and pi(π) ______ bonds respectively present in hex-1-en-4-yne are:
Answer
(C)
13 and 3
18
Which among the following halides will generate the most stable carbocation in the nucleophilic substitution reaction?
Answer
(B)
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Haloalkanes and Haloarenes Question 11 English Option 2
19

Drug $X$ becomes ineffective after $50 \%$ decomposition. The original concentration of drug in a bottle was $16 \mathrm{mg} / \mathrm{mL}$ which becomes $4 \mathrm{mg} / \mathrm{mL}$ in 12 months. The expiry time of the drug in months is _________.

Assume that the decomposition of the drug follows first order kinetics.

Answer
(C)
6
20

$\mathrm{O}_2$ gas will be evolved as a product of electrolysis of :

(A) an aqueous solution of $\mathrm{AgNO}_3$ using silver electrodes.

(B) an aqueous solution of $\mathrm{AgNO}_3$ using platinum electrodes.

(C) a dilute solution of $\mathrm{H}_2 \mathrm{SO}_4$ using platinum electrodes.

(D) a high concentration solution of $\mathrm{H}_2 \mathrm{SO}_4$ using platinum electrodes.

Choose the correct answer from the options given below :

Answer
(A)
(B) and (C) only
21
Total number of non-bonded electrons present in NO2$-$ ion based on Lewis theory is ______.
Answer
12
22

Consider the following low-spin complexes

$$ \mathrm{K}_3\left[\mathrm{Co}\left(\mathrm{NO}_2\right)_6\right], \mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right], \mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right], \mathrm{Cu}_2\left[\mathrm{Fe}(\mathrm{CN})_6\right] \text { and } \mathrm{Zn}_2\left[\mathrm{Fe}(\mathrm{CN})_6\right] $$

The sum of the spin-only magnetic moment values of complexes having yellow colour is ________ B.M. (answer in nearest integer)

Answer
0
23

In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is __________ $\times 10^{-1} \%$.

(Molar mass : $\mathrm{O}=16, \mathrm{~S}=32, \mathrm{Ba}=137$ in $\mathrm{g} ~\mathrm{mol}^{-1}$ )

Answer
275
24
In the Claisen-Schmidt reaction to prepare, dibenzalacetone from 5.3 g of benzaldehyde, a total of 3.51 g of product was obtained. The percentage yield in this reaction was _______ %.
Answer
60
25

Isomeric hydrocarbons → negative Baeyer’s test

(Molecular formula C9H12)

The total number of isomers from above with four different non-aliphatic substitution sites is -

Answer
2