JEE Main 2025 Jan 28 Shift 2 — Chemistry

Which of the following is/are not correct with respect to energy of atomic orbitals of hydrogen atom?

(A) $1s < 2p < 3d < 4s$ (B) $1s < 2s = 2p < 3s = 3p$ (C) $1s < 2s < 2p < 3s < 3p$ (D) $1s < 2s < 4s < 3d$

Choose the correct answer from the options given below :

An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path $A \to B \to C \to D \to A$ as shown in the three cases above.

Choose the correct option regarding $\Delta U$ :

three $V$ (dm$^3$) vs $p$ (kPa) plots — Case-I (curved loop A-B-C-D), Case-II (rectangular loop), Case-III (rhombus/diamond loop), each a closed cyclic path A→B→C→D→A

Assume a living cell with $0.9\%\,(\omega/\omega)$ of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water.

(Consider the data upto first decimal place only)

The cell will :

Concentrated nitric acid is labelled as 75% by mass. The volume in mL of the solution which contains 30 g of nitric acid is __________.

Given : Density of nitric acid solution is $1.25\ \mathrm{g/mL}$.

Arrange the following in increasing order of solubility product :

$\mathrm{Ca(OH)_2},\ \mathrm{AgBr},\ \mathrm{PbS},\ \mathrm{HgS}$

For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth?

Where N - Number of Bacteria at any time, $N_0$ - Initial number of Bacteria.

Consider an elementary reaction

$$A(g) + B(g) \to C(g) + D(g)$$

If the volume of reaction mixture is suddenly reduced to $\dfrac{1}{3}$ of its initial volume, the reaction rate will become $'x'$ times of the original reaction rate. The value of $x$ is :

Identify the inorganic sulphides that are yellow in colour :

(A) $\mathrm{(NH_4)_2S}$ (B) $\mathrm{PbS}$ (C) $\mathrm{CuS}$ (D) $\mathrm{As_2S_3}$ (E) $\mathrm{As_2S_5}$

Choose the correct answer from the options given below :

Given below are two statements :

Statement (I) : According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.

Statement (II) : Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.

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

The amphoteric oxide among $\mathrm{V_2O_3}$, $\mathrm{V_2O_4}$ and $\mathrm{V_2O_5}$, upon reaction with alkali leads to formation of an oxide anion. The oxidation state of V in the oxide anion is :

Match List-I with List-II :

List-I (Complex)	List-II (Hybridisation of central metal ion)
(A) $\mathrm{[CoF_6]^{3-}}$	(I) $d^2sp^3$
(B) $\mathrm{[NiCl_4]^{2-}}$	(II) $sp^3$
(C) $\mathrm{[Co(NH_3)_6]^{3+}}$	(III) $sp^3d^2$
(D) $\mathrm{[Ni(CN)_4]^{2-}}$	(IV) $dsp^2$

Choose the correct answer from the options given below :

The purification method based on the following physical transformation is :

$$\underset{(X)}{\text{Solid}} \xrightarrow{\text{Heat}} \underset{(X)}{\text{Vapour}} \xrightarrow{\text{Cool}} \underset{(X)}{\text{Solid}}$$

Given below are two statements :

Statement (I) :

a cyclopentane ring

and

an open-chain alkene, CH$_3$CH$_2$CH=CHCH$_2$CH$_3$

are isomeric compounds.

Statement (II) :

a primary amine, CH$_3$(CH$_2$)$_4$CH$_2$NH$_2$

and

a secondary amine, CH$_3$CH$_2$CH$_2$–NH–CH$_2$CH$_2$CH$_3$

are functional group isomers.

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

Identify product [A], [B] and [C] in the following reaction sequence.

\mathrm{CH_3 - C \equiv CH} \xrightarrow[\mathrm{H_2}]{\mathrm{Pd/C}} [A] \xrightarrow[\text{(ii) Zn, H_2O}]{\text{(i) O_3}} [B] + [C]

The major product of the following reaction is :

a dibromide bearing a phenyl group — 4-phenyl chain with two bromine atoms on adjacent-region carbons — treated with excess KOH/EtOH, $\Delta$ (double dehydrohalogenation)

The product B formed in the following reaction sequence is :

$$\text{4-methyl-(prop-1-en-1-yl)benzene} \xrightarrow[\text{(Major)}]{\mathrm{HCl}} (A) \xrightarrow[\text{(Major)}]{\mathrm{AgCN}} (B)$$

reactant is 1-(prop-1-en-1-yl)-4-methylbenzene, i.e. p-tolyl–CH=CH–CH$_3$

The total number of compounds from below when treated with hot $\mathrm{KMnO_4}$ giving benzoic acid is :

eight compounds — toluene, ethylbenzene, isopropylbenzene (cumene), tert-butylbenzene, isobutylbenzene, 2-phenylpropan-2-ol, n-propylbenzene, 4,4'-dimethylbiphenyl

Identify correct statements :

(A) Primary amines do not give diazonium salts when treated with $\mathrm{NaNO_2}$ in acidic condition. (B) Aliphatic and aromatic primary amines on heating with $\mathrm{CHCl_3}$ and ethanolic KOH form carbylamines. (C) Secondary and tertiary amines also give carbylamine test. (D) Benzenesulfonyl chloride is known as Hinsberg's reagent. (E) Tertiary amines reacts with benzenesulfonyl chloride very easily.

Choose the correct answer from the options given below :

Match List-I with List-II :

List-I (Saccharide)	List-II (Glycosidic linkage present)
(A) Sucrose	(I) $\alpha\,1-4$
(B) Maltose	(II) $\alpha\,1-4$ and $\alpha\,1-6$
(C) Lactose	(III) $\alpha\,1-\beta\,2$
(D) Amylopectin	(IV) $\beta\,1-4$

Choose the correct answer from the options given below :

Identify correct conversion during acidic hydrolysis from the following :

(A) starch gives galactose. (B) cane sugar gives equal amount of glucose and fructose. (C) milk sugar gives glucose and galactose. (D) amylopectin gives glucose and fructose. (E) amylose gives only glucose.

Choose the correct answer from the options given below :

Consider the following data :

Heat of formation of $\mathrm{CO_2(g)} = -393.5\ \mathrm{kJ\ mol^{-1}}$ Heat of formation of $\mathrm{H_2O(l)} = -286.0\ \mathrm{kJ\ mol^{-1}}$ Heat of combustion of benzene $= -3267.0\ \mathrm{kJ\ mol^{-1}}$

The heat of formation of benzene is __________ $\mathrm{kJ\ mol^{-1}}$.

(Nearest integer)

Electrolysis of 600 mL aqueous solution of NaCl for 5 min changes the pH of the solution to 12. The current in Amperes used for the given electrolysis is __________. (Nearest integer).

Total number of molecules/species from following which will be paramagnetic is __________.

$\mathrm{O_2},\ \mathrm{O_2^{+}},\ \mathrm{O_2^{-}},\ \mathrm{NO},\ \mathrm{NO_2},\ \mathrm{CO},\ \mathrm{K_2[NiCl_4]},\ \mathrm{[Co(NH_3)_6]Cl_3},\ \mathrm{K_2[Ni(CN)_4]}$

A group 15 element forms $d\pi - d\pi$ bond with transition metals. It also forms hydride, which is a strongest base among the hydrides of other group members that form $d\pi - d\pi$ bond. The atomic number of the element is __________.

The spin only magnetic moment ($\mu$) value (B.M.) of the compound with strongest oxidising power among $\mathrm{Mn_2O_3}$, $\mathrm{TiO}$ and $\mathrm{VO}$ is __________ B.M. (Nearest integer).