JEE Main 2025 Apr 4 Shift 2 — Chemistry

Consider the ground state of chromium atom $(Z = 24)$. How many electrons are with Azimuthal quantum number $l = 1$ and $l = 2$ respectively ?

Consider the given data :

(a) $\mathrm{HCl(g) + 10\ H_2O(l) \rightarrow HCl.10\ H_2O}$ $\Delta H = -69.01\ \mathrm{kJ\ mol^{-1}}$

(b) $\mathrm{HCl(g) + 40\ H_2O(l) \rightarrow HCl.40\ H_2O}$ $\Delta H = -72.79\ \mathrm{kJ\ mol^{-1}}$

Choose the correct statement :

Given below are two statements :

Statement (I) : Molal depression constant $\mathrm{K}_f$ is given by $\frac{\mathrm{M_1 R T}_f}{\Delta \mathrm{S_{fus}}}$, where symbols have their usual meaning.

Statement (II) : $\mathrm{K}_f$ for benzene is less than the $\mathrm{K}_f$ for water.

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

Half life of zero order reaction A $\rightarrow$ product is 1 hour, when initial concentration of reactant is $2.0\ \mathrm{mol\ L^{-1}}$. The time required to decrease concentration of A from 0.50 to $0.25\ \mathrm{mol\ L^{-1}}$ is :

Consider the following plots of log of rate constant k (log k) vs $\frac{1}{\mathrm{T}}$ for three different reactions. The correct order of activation energies of these reactions is :

log k vs 1/T plot showing three straight lines labelled 1, 2 and 3 — line 1 has a moderately steep negative slope, line 2 is the steepest (nearly vertical), and line 3 is nearly flat with a shallow negative slope

Given below are two statements :

Statement (I) : For $\mathrm{ClF_3}$ (Cl bearing two lone pairs), all three possible structures may be drawn as follows.

three trigonal-bipyramidal structures of ClF3 — I: both lone pairs axial, all three F equatorial; II: one lone pair axial and one equatorial; III: both lone pairs equatorial, T-shaped with two axial F and one equatorial F

Statement (II) : Structure III is most stable, as the orbitals having the lone pairs are axial, where the lp – bp repulsion is minimum.

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

The elements of Group 13 with highest and lowest first ionisation enthalpies are respectively :

Given below are two statements :

Statement (I) : The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13.

Statement (II) : Melting points and boiling points of group 13 elements are in general much higher than those of corresponding elements of group 14.

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

'X' is the number of electrons in $t_{2g}$ orbitals of the most stable complex ion among $\mathrm{[Fe(NH_3)_6]^{3+}}$, $\mathrm{[FeCl_6]^{3-}}$, $\mathrm{[Fe(C_2O_4)_3]^{3-}}$ and $\mathrm{[Fe(H_2O)_6]^{3+}}$. The nature of oxide of vanadium of the type $\mathrm{V_2O_X}$ is :

The correct order of $\mathrm{[FeF_6]^{3-}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Ni(CO)_4]}$ and $\mathrm{[Ni(CN)_4]^{2-}}$ complex species based on the number of unpaired electrons present is :

The incorrect relationship in the following pairs in relation to ionisation enthalpies is :

Match List - I with List - II.

List - I (Separation of)	List - II (Separation Technique)
(A) Aniline from aniline-water mixture	(I) Simple distillation
(B) Glycerol from spent-lye in soap industry	(II) Fractional distillation
(C) Different fractions of crude oil in petroleum industry	(III) Distillation at reduced pressure
(D) Chloroform-Aniline mixture	(IV) Steam distillation

Choose the correct answer from the options given below :

In which pairs, the first ion is more stable than the second ?

four pairs of ions —* (A) cyclohexyl cation bearing an $\mathrm{-OMe}$ group on the cationic carbon & cyclohexyl cation bearing a $\mathrm{-Me}$ group on the cationic carbon; (B) cyclohexyl carbanion with an ortho-nitrophenyl group on the carbanion carbon & cyclohexyl cation with an ortho-nitrophenyl group on the cationic carbon; (C) cyclohexylmethyl cation ($\mathrm{CH_2^+}$ on a saturated cyclohexane ring) & (cyclohex-1-en-1-yl)methyl cation ($\mathrm{CH_2^+}$ attached to the ring double-bond carbon, allylic); *(D) trimethyl carbocation $\mathrm{(Me)_3C^+}$ & dimethyl(methoxy) carbocation $\mathrm{Me_2C^+(OMe)}$

The IUPAC name of the following compound is :

$$\mathrm{HC \equiv C - CH_2 - \underset{\underset{\displaystyle \mathrm{OH}}{|}}{CH} - CH_2 - CH = CH_2}$$

Consider the following molecule (X).

The structure of X is

a tricyclic hydrocarbon (X) made of two fused six-membered rings and one fused five-membered ring, containing three C=C double bonds — a conjugated diene across the two six-membered rings and one double bond at the ring fusion of the five-membered ring

The major product formed when the given molecule (X) is treated with HBr (1 eq) is :

Given below are two statements :

Statement (I) : Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction.

Statement (II) : In alcoholic potassium hydroxide, alkyl chlorides form alkenes by abstracting the hydrogen from the $\beta$-carbon.

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

Which among the following compounds give yellow solid when reacted with NaOI/NaOH ?

(A) $\mathrm{CH_3-\underset{\underset{\displaystyle \mathrm{OH}}{|}}{CH}-C_2H_5}$

(B) $\mathrm{CH_3-CH_2-CH_2-OH}$

(C) $\mathrm{CH_3-CO-C_2H_5}$

(D) $\mathrm{CH_3-COOH}$

(E) $\mathrm{CH_3-CH_2-CHO}$

Choose the correct answer from the options given below :

A toxic compound "A" when reacted with NaCN in aqueous acidic medium yields an edible cooking component and food preservative "B". "B" is converted to "C" by diborane and can be used as an additive to petrol to reduce emission. "C" upon reaction with oleum at $140°\mathrm{C}$ yields an inhalable anesthetic "D". Identify "A", "B", "C" & "D", respectively :

The correct order of basicity for the following molecules is :

three cyclic amide structures —* (P) N-methylpiperidin-2-one (six-membered saturated lactam with N–Me); (Q) N-methyl-5,6-dihydropyridin-2(1H)-one (six-membered lactam with N–Me and a C=C conjugated with the C=O); *(R) a bridged bicyclic lactam (1-azabicyclo[2.2.2

octan-2-one type) in which the nitrogen lone pair cannot conjugate with the C=O]*

A dipeptide, "$x$" on complete hydrolysis gives "$y$" and "$z$". "$y$" on treatment with aq. $\mathrm{HNO_2}$ produces lactic acid. On the other hand "$z$" on heating gives the following cyclic molecule.

2,5-diketopiperazine (glycine anhydride) — a six-membered ring with two NH groups and two C=O groups alternating with two CH2 groups

Based on the information given, the dipeptide X is :

$x$ mg of $\mathrm{Mg(OH)_2}$ (molar mass = 58) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of $x$ is _________ mg. (Nearest integer)

(Given : $\mathrm{Mg(OH)_2}$ is assumed to dissociate completely in $\mathrm{H_2O}$]

The molar conductance of an infinitely dilute solution of ammonium chloride was found to be $185\ \mathrm{S\ cm^2\ mol^{-1}}$ and the ionic conductance of hydroxyl and chloride ions are 170 and $70\ \mathrm{S\ cm^2\ mol^{-1}}$, respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is $85.5\ \mathrm{S\ cm^2\ mol^{-1}}$, its degree of dissociation is given by $x \times 10^{-1}$.

The value of $x$ is _________. (Nearest integer)

Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of $2\ \mathrm{g\ mL^{-1}}$. The concentration of dissolved oxygen $(\mathrm{O_2})$ in sea water is 5.8 ppm. Then the concentration of dissolved oxygen $(\mathrm{O_2})$ in sea water, is $x \times 10^{-4}$ m.

$x =$ _________. (Nearest integer)

Given : Molar mass of NaCl is $58.5\ \mathrm{g\ mol^{-1}}$

Molar mass of $\mathrm{O_2}$ is $32\ \mathrm{g\ mol^{-1}}$

The amount of calcium oxide produced on heating 150 kg limestone (75% pure) is _________ kg. (Nearest integer)

Given : Molar mass (in $\mathrm{g\ mol^{-1}}$) of Ca-40, O-16, C-12

A metal complex with a formula $\mathrm{MCl_4.3NH_3}$ is involved in $sp^3d^2$ hybridisation. It upon reaction with excess of $\mathrm{AgNO_3}$ solution gives '$x$' moles of AgCl. Consider '$x$' is equal to the number of lone pairs of electron present in central atom of $\mathrm{BrF_5}$. Then the number of geometrical isomers exhibited by the complex is _________.