JEE Main 2025 Apr 8 Shift 2 — Chemistry

Correct statements for an element with atomic number 9 are

A. There can be 5 electrons for which $m_s = +\frac{1}{2}$ and 4 electrons for which $m_s = -\frac{1}{2}$

B. There is only one electron in $\mathrm{p_z}$ orbital.

C. The last electron goes to orbital with $n = 2$ and $l = 1$.

D. The sum of angular nodes of all the atomic orbitals is 1.

Choose the correct answer from the options given below:

Which of the following binary mixture does not show the behaviour of minimum boiling azeotropes?

$$\mathrm{HA}(aq) \rightleftharpoons \mathrm{H^+}(aq) + \mathrm{A^-}(aq)$$

The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 °C. The dissociation constant for the acid is

Given : $K_f(\mathrm{H_2O}) = 1.8\ \mathrm{K\ kg\ mol^{-1}}$, molality = molarity

In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are $t_1$ and $t_2$ (s), respectively. The ratio $t_1/t_2$ will be:

The number of species from the following that are involved in $\mathrm{sp^3d^2}$ hybridization is

$\mathrm{[Co(NH_3)_6]^{3+}}$, $\mathrm{SF_6}$, $\mathrm{[CrF_6]^{3-}}$, $\mathrm{[CoF_6]^{3-}}$, $\mathrm{[Mn(CN)_6]^{3-}}$ and $\mathrm{[MnCl_6]^{3-}}$

The atomic number of the element from the following with lowest $1^{st}$ ionisation enthalpy is :

Given below are two statements:

Statement I : $\mathrm{H_2Se}$ is more acidic than $\mathrm{H_2Te}$

Statement II : $\mathrm{H_2Se}$ has higher bond enthalpy for dissociation than $\mathrm{H_2Te}$

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

The correct decreasing order of spin only magnetic moment values (BM) of $\mathrm{Cu^+}$, $\mathrm{Cu^{2+}}$, $\mathrm{Cr^{2+}}$ and $\mathrm{Cr^{3+}}$ ions is :

Given below are two statements:

Statement I : A homoleptic octahedral complex, formed using monodentate ligands, will not show stereoisomerism

Statement II : cis– and trans – platin are heteroleptic complexes of Pd.

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

Match the LIST-I with LIST-II

	LIST-I (Complex/ Species)		LIST-II (Shape & magnetic moment)
A.	$\mathrm{[Ni(CO)_4]}$	I.	Tetrahedral, 2.8 BM
B.	$\mathrm{[Ni(CN)_4]^{2-}}$	II.	Square planar, 0 BM
C.	$\mathrm{[NiCl_4]^{2-}}$	III.	Tetrahedral, 0 BM
D.	$\mathrm{[MnBr_4]^{2-}}$	IV.	Tetrahedral, 5.9 BM

Choose the correct answer from the options given below:

Match the LIST-I with LIST-II

	LIST-I (Reagent)		LIST-II (Functional Group detected)
A.	Sodium bicarbonate solution	I.	double bond/ unsaturation
B.	Neutral ferric chloride	II.	carboxylic acid
C.	ceric ammonium nitrate	III.	phenolic - OH
D.	alkaline $\mathrm{KMnO_4}$	IV.	alcoholic - OH

Choose the correct answer from the options given below:

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g $\mathrm{H_2O}$ and 0.307 g $\mathrm{CO_2}$. The percentages of hydrogen and oxygen in the given organic compound respectively are:

What is the correct IUPAC name of

a cyclopentene ring bearing an $-\mathrm{OH}$ group on one ring carbon and an ethyl substituent on another ring carbon

?

Match the LIST-I with LIST-II

	LIST-I		LIST-II
A.	Carbocation	I.	Species that can supply a pair of electrons.
B.	C-Free radical	II.	Species that can receive a pair of electrons.
C.	Nucleophile	III.	$\mathrm{sp^2}$ hybridized carbon with empty p-orbital.
D.	Electrophile	IV.	$\mathrm{sp^2/sp^3}$ hybridized carbon with one unpaired electron.

Choose the correct answer from the options given below:

1,2-dibromocyclooctane $\xrightarrow{\text{(i) KOH (alc.) (ii) } \mathrm{NaNH_2} \text{ (iii) } \mathrm{Hg^{2+}/H^+} \text{ (iv) } \mathrm{Zn{-}Hg/H^+}}$ P (major product)

'P' is

Choose the correct set of reagents for the following conversion.

Ethyl benzene $\longrightarrow$

benzene ring with a $\mathrm{CH{=}CH_2}$ group and a Br at the para position (4-bromostyrene)

Which one of the following reactions will not lead to the desired ether formation in major proportion ?

(iso–Bu $\Rightarrow$ isobutyl, sec–Bu $\Rightarrow$ sec-butyl, nPr $\Rightarrow$ n–propyl, $^t$Bu $\Rightarrow$ tert–butyl, Et $\Rightarrow$ ethyl)

When

keto-aldehyde $\mathrm{CH_3CO(CH_2)_4CHO}$ (6-oxoheptanal, drawn as a zig-zag chain with a methyl ketone at one end and -CHO at the other)

undergoes intramolecular aldol condensation, the major product formed is :

$$\mathrm{A \xrightarrow[(ii)\ H_3O^+]{(i)\ NaOH} B \xrightarrow[(ii)\ H_2SO_4,\ \Delta]{(i)\ EtOH} C}$$

'A' shows positive Lassaign's test for N and its molar mass is 121.

'B' gives effervescence with aq $\mathrm{NaHCO_3}$.

'C' gives fruity smell.

Identify A, B and C from the following.

$$\mathrm{H_2N{-}\underset{\underset{\mathrm{CH(CH_3)_2}}{|}}{CH}{-}COOH}$$

The above amino acid is taken to $\mathrm{pH = 2}$ (giving A) and to $\mathrm{pH = 10}$ (giving B).

Choose the correct option for structures of A and B, respectively

20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is __________ M. (Nearest Integer value)

(Given : Na = 23, I = 127, Ag = 108, N = 14, O = 16 g mol$^{-1}$)

The energy of an electron in first Bohr orbit of H-atom is $-13.6$ eV. The magnitude of energy value of electron in the first excited state of $\mathrm{Be^{3+}}$ is __________ eV (nearest integer value)

Resonance in $\mathrm{X_2Y}$ can be represented as

$$\overset{\ominus}{\ddot{X}}{=}X{=}\overset{\oplus}{\ddot{Y}} \longleftrightarrow \overset{\oplus}{X}{\equiv}X{-}\overset{\ominus}{\ddot{Y}}{:}$$

The enthalpy of formation of $\mathrm{X_2Y}$ $\left(\mathrm{X{=}X}(g) + \frac{1}{2}\mathrm{Y{=}Y}(g) \rightarrow \mathrm{X_2Y}(g)\right)$ is 80 kJ mol$^{-1}$. The magnitude of resonance energy of $\mathrm{X_2Y}$ is __________ kJ mol$^{-1}$ (nearest integer value)

Given : Bond energies of $\mathrm{X \equiv X}$, $\mathrm{X = X}$, $\mathrm{Y = Y}$ and $\mathrm{X = Y}$ are 940, 410, 500 and 602 kJ mol$^{-1}$ respectively.

valence X: 3 , Y: 2

The equilibrium constant for decomposition of $\mathrm{H_2O}$ (g)

$$\mathrm{H_2O(g) \rightleftharpoons H_2(g) + \frac{1}{2}O_2(g)} \quad (\Delta G^\circ = 92.34\ \mathrm{kJ\ mol^{-1}})$$

is $8.0 \times 10^{-3}$ at 2300 K and total pressure at equilibrium is 1 bar. Under this condition, the degree of dissociation ($\alpha$) of water is __________ $\times 10^{-2}$ (nearest integer value).

[Assume $\alpha$ is negligible with respect to 1]

Consider the following half cell reaction

$$\mathrm{Cr_2O_7^{2-}(aq) + 6e^- + 14H^+(aq) \longrightarrow 2Cr^{3+}(aq) + 7H_2O(l)}$$

The reaction was conducted with the ratio of $\frac{[\mathrm{Cr^{3+}}]^2}{[\mathrm{Cr_2O_7^{2-}}]} = 10^{-6}$. The pH value at which the EMF of the half cell will become zero is __________. (nearest integer value)

[Given : standard half cell reduction potential $E^{\circ}_{\mathrm{Cr_2O_7^{2-},\ H^+/Cr^{3+}}} = 1.33\ \mathrm{V}$, $\frac{2.303RT}{F} = 0.059\ \mathrm{V}$]