JEE Main 2025 Jan 23 Shift 2 — Chemistry

Given below are two statements :

Statement (I) : For a given shell, the total number of allowed orbitals is given by $n^2$.

Statement (II) : For any subshell, the spatial orientation of the orbitals is given by $-l$ to $+l$ values including zero.

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

The effect of temperature on spontaneity of reactions are represented as :

	$\Delta H$	$\Delta S$	Temperature	Spontaneity
(A)	$+$	$-$	any T	Non spontaneous
(B)	$+$	$+$	low T	spontaneous
(C)	$-$	$-$	low T	Non spontaneous
(D)	$-$	$+$	any T	spontaneous

The incorrect combinations are :

Standard electrode potentials for a few half cells are mentioned below :

$$E^{\circ}_{Cu^{2+}/Cu} = 0.34\ \mathrm{V},\quad E^{\circ}_{Zn^{2+}/Zn} = -0.76\ \mathrm{V}$$

$$E^{\circ}_{Ag^{+}/Ag} = 0.80\ \mathrm{V},\quad E^{\circ}_{Mg^{2+}/Mg} = -2.37\ \mathrm{V}$$

Which one of the following cells gives the most negative value of $\Delta G^{\circ}$ ?

When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if decrease in vapour pressure is 20 mm of Hg ?

Consider a binary solution of two volatile liquid components 1 and 2. $x_1$ and $y_1$ are the mole fractions of component 1 in liquid and vapour phase, respectively. The slope and intercept of the linear plot of $\dfrac{1}{x_1}$ vs $\dfrac{1}{y_1}$ are given respectively as :

Consider the reaction

$$X_2Y(g) \rightleftharpoons X_2(g) + \tfrac{1}{2}Y_2(g)$$

The equation representing correct relationship between the degree of dissociation $(x)$ of $X_2Y(g)$ with its equilibrium constant $K_p$ is ________.

Assume $x$ to be very very small.

Which of the following graphs most appropriately represents a zero order reaction ?

pH of water is 7 at $25^{\circ}\mathrm{C}$. If water is heated to $80^{\circ}\mathrm{C}$, it's pH will :

Given below are two statements about X-ray spectra of elements :

Statement (I) : A plot of $\sqrt{\nu}$ ($\nu =$ frequency of X-rays emitted) vs atomic mass is a straight line.

Statement (II) : $\nu$ ($\nu =$ frequency of X-rays emitted) vs atomic number is a straight line.

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

Below are given the atomic numbers of a few elements of group 14. The atomic number of the element with the lowest melting point is :

Consider the following reactions

$$\mathrm{K_2Cr_2O_7} \xrightarrow[-H_2O]{\text{KOH}} [A] \xrightarrow[-H_2O]{\text{H}_2\text{SO}_4} [B] + \mathrm{K_2SO_4}$$

The products [A] and [B], respectively are :

Match List-I with List-II.

	List-I		List-II
(A)	Bronze	(I)	Cu, Ni
(B)	Brass	(II)	Fe, Cr, Ni, C
(C)	UK silver coin	(III)	Cu, Zn
(D)	Stainless steel	(IV)	Cu, Sn

Choose the correct answer from the options given below :

Identify the coordination complexes in which the central metal ion has $d^4$ configuration.

(A) $\mathrm{[FeO_4]^{2-}}$

(B) $\mathrm{[Mn(CN)_6]^{3-}}$

(C) $\mathrm{[Fe(CN)_6]^{3-}}$

(D) $\mathrm{Cr_2(O{-}\overset{\overset{\textstyle O}{\|}}{C}{-}Me)_4(H_2O)_2}$ (chromium(II) acetate dimer)

(E) $\mathrm{[NiF_6]^{2-}}$

Choose the correct answer from the options given below :

Identify A, B and C in the given below reaction sequence

$$[A] \xrightarrow{\text{HNO}_3} \mathrm{Pb(NO_3)_2} \xrightarrow{\text{H}_2\text{SO}_4} [B] \xrightarrow[\substack{(2)\ \text{Acetic acid}\\ (3)\ \mathrm{K_2CrO_4}}]{(1)\ \text{Ammonium acetate}} [C]\ (\text{Yellow ppt})$$

Consider the following reaction

$$\mathrm{R{-}\overset{\overset{\textstyle O}{\|}}{C}{-}R} + H_2O \underset{}{\overset{K}{\rightleftharpoons}} \mathrm{R{-}\underset{\underset{\textstyle OH}{|}}{\overset{\overset{\textstyle OH}{|}}{C}}{-}R}$$

Statement (I) : In the case of formaldehyde ($\mathrm{H{-}\overset{\overset{\textstyle O}{\|}}{C}{-}H}$), K is about 2280, due to small substituents, hydration is faster.

Statement (II) : In the case of trichloro acetaldehyde ($\mathrm{H{-}\overset{\overset{\textstyle O}{\|}}{C}{-}CCl_3}$), K is about 2000 due to $-I$ effect of $-Cl$.

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

Match List-I (Isomers of $\mathrm{C_{10}H_{14}}$) with List-II (Ozonolysis product).

List-I shows four bicyclic hydrocarbon structures (methyl-substituted hydrindane/indane-type fused 6- and 5-membered rings, each with one ring double bond) labelled (A), (B), (C), (D); List-II shows four open-chain poly-carbonyl ozonolysis products labelled (I)-(IV).

• (A) 2-methyl bicyclic isomer with double bond in the six-membered ring
• (B) 2-methyl isomer with double bond at the ring fusion / five-membered ring
• (C) 6-methyl isomer with double bond in the six-membered ring
• (D) 1-methyl isomer with the double bond conjugated to the ring junction

List-II products:

• (I) $\mathrm{H{-}CO{-}CH(CH_3){-}CH_2{-}CO{-}(CH_2)_3{-}CO{-}CHO}$ type dialdehyde/diketone with a branch methyl
• (II) $\mathrm{CH_3{-}CO{-}CO{-}(CH_2)_4{-}CO{-}CHO}$ type
• (III) $\mathrm{H{-}CO{-}CH_2CH_2{-}CO{-}CH(CH_3){-}CO{-}CHO}$ type (two terminal CHO, a mid ketone and a branch methyl)
• (IV) $\mathrm{H{-}CO{-}CO{-}(CH_2)_4{-}CO{-}CO{-}CH_3}$ type

Choose the correct answer from the options given below :

The ascending order of relative rate of solvolysis of following compounds is :

four bromo compounds

• (A) 1-bromo-3,3,5,5-tetramethylcyclohexane (tertiary bromide on a gem-dimethyl-substituted cyclohexane ring)
• (B) 1-bromo-1,2,3,4-tetrahydronaphthalene (benzylic secondary bromide, with a methyl at the 4-position)
• (C) bromodiphenylmethane, $\mathrm{(C_6H_5)_2CHBr}$ (dibenzylic secondary bromide)
• (D) 3-bromo-2-methylpentane (a secondary alkyl bromide)

Identify the products [A] and [B], respectively in the following reaction :

$$\text{Chlorobenzene} \xrightarrow[\text{(ii) } H^{+}]{\text{(i) NaOH, 623 K, 300 atm}} [A] \xrightarrow[\text{H}_2\text{SO}_4]{\text{Na}_2\text{Cr}_2\text{O}_7} [B]$$

Given below are two statements :

Statement (I) : The boiling points of alcohols and phenols increase with increase in the number of C-atoms.

Statement (II) : The boiling points of alcohols and phenols are higher in comparison to other class of compounds such as ethers, haloalkanes.

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

The $\alpha$-Helix and $\beta$-Pleated sheet structures of protein are associated with its :

When 81.0 g of aluminium is allowed to react with 128.0 g of oxygen gas, the mass of aluminium oxide produced in grams is ________. (Nearest integer)

Given :

Molar mass of Al is $27.0\ \mathrm{g\ mol^{-1}}$

Molar mass of O is $16.0\ \mathrm{g\ mol^{-1}}$

The bond dissociation enthalpy of $X_2$, $\Delta H^{\circ}_{\text{bond}}$ calculated from the given data is ________ $\mathrm{kJ\ mol^{-1}}$. (Nearest integer)

$$\mathrm{M^{+}X^{-}(s) \rightarrow M^{+}(g) + X^{-}(g)} \quad \Delta H^{\circ}_{\text{lattice}} = 800\ \mathrm{kJ\ mol^{-1}}$$

$$\mathrm{M(s) \rightarrow M(g)} \quad \Delta H^{\circ}_{\text{sub}} = 100\ \mathrm{kJ\ mol^{-1}}$$

$$\mathrm{M(g) \rightarrow M^{+}(g) + e^{-}(g)} \quad \Delta H^{\circ}_{i} = 500\ \mathrm{kJ\ mol^{-1}}$$

$$\mathrm{X(g) + e^{-}(g) \rightarrow X^{-}(g)} \quad \Delta H^{\circ}_{\text{eg}} = -300\ \mathrm{kJ\ mol^{-1}}$$

$$\mathrm{M(s) + \tfrac{1}{2}X_2(g) \rightarrow M^{+}X^{-}(s)} \quad \Delta H^{\circ}_{f} = -400\ \mathrm{kJ\ mol^{-1}}$$

[Given : $\mathrm{M^{+}X^{-}}$ is a pure ionic compound and X forms a diatomic molecule $X_2$ in gaseous state]

0.01 mole of an organic compound (X) containing 10% hydrogen, on complete combustion produced 0.9 g $\mathrm{H_2O}$. Molar mass of (X) is ________ $\mathrm{g\ mol^{-1}}$.

A compound 'X' absorbs 2 moles of hydrogen and 'X' upon oxidation with $\mathrm{KMnO_4\,|\,H^{+}}$ gives $\mathrm{CH_3{-}\overset{\overset{\textstyle O}{\|}}{C}{-}CH_3}$, $\mathrm{CH_3{-}\overset{\overset{\textstyle O}{\|}}{C}{-}OH}$ and $\mathrm{CH_3{-}\overset{\overset{\textstyle O}{\|}}{C}{-}CH_2CH_2{-}\overset{\overset{\textstyle O}{\|}}{C}{-}OH}$.

The total number of $\sigma$ bonds present in the compound 'X' is ________.

Consider the following sequence of reactions.

reaction scheme

4-ethoxyaniline (p-ethoxyaniline) $\xrightarrow[\text{0-5}^{\circ}\text{C}]{\text{(i) NaNO}_2,\ \text{HCl}}$ (A, the diazonium salt) $\xrightarrow[\text{(ii) dil. HCl}]{\text{(i) phenol, NaOH}}$ (B) (Molecular formula $\mathrm{C_{14}H_{14}N_2O_2}$) $\xrightarrow[\text{(ii) } \mathrm{H_3CCH_2Br}]{\text{(i) NaOH}}$ (C) (Molecular formula $\mathrm{C_{16}H_{18}N_2O_2}$)

Total number of $sp^3$ hybridised carbon atoms in the major product C formed is ________.