Column J (Molecule)	Column K (BDE in kcal/mol)
(P) $\mathbf{H}-\mathrm{CH}(\mathrm{CH}_3)_2$	(i) 132
(Q) $\mathbf{H}-\mathrm{CH}_2\mathrm{Ph}$	(ii) 110
(R) $\mathbf{H}-\mathrm{CH}=\mathrm{CH}_2$	(iii) 95
(S) $\mathrm{H}-\mathrm{C} \equiv \mathrm{CH}$	(iv) 88

Easy•Carboxylic Acids

Which is the strongest acid among the following?

Easy•Chemical Bonding

[JEE Mains 2026] In HNO₃, the formal charges on oxygen atoms bonded to nitrogen are: one oxygen is double-bonded (O=N), one is single-bonded (O-N), and one is in the hydroxyl group (O-H). What are the formal charges on the double-bonded oxygen, single-bonded oxygen, and the oxygen in -OH group respectively?

Easy•Chemical Bonding

The hybridization of the central atom in

\text{XeF}_4

is:

Easy•Chemical Equilibrium

For

N_2 + 3H_2 \rightleftharpoons 2NH_3 + \text{heat}

, the yield of

NH_3

increases by:

Easy•Chemical Kinetics

[JEE Mains 2026] Three experiments are running in separate vessels, following first-order kinetics with the same rate constant k: Experiment-(A): 100 ml, 10 M Experiment-(B): 200 ml, 10 M Experiment-(C): 100 ml, 10 M + 100 ml H₂O What is the correct order of rate of reaction in the above experiments?

Easy•Chemical Kinetics

For a first-order reaction, if the rate constant is 0.0693 min⁻¹, the half-life of the reaction is:

Easy•Coordination Compounds

In the complex [Co(NH₃)₅Cl]Cl₂, the oxidation state and coordination number of cobalt are respectively:

Easy•Coordination

The IUPAC name of

[Pt(NH_3)_2Cl_2]

is:

Medium•Coordination Compounds

In the complex

[\text{Co}(\text{en})_2\text{Cl}_2]^+

, the oxidation state and coordination number of cobalt are respectively:

Easy•Haloalkanes

Which of the following undergoes SN1 reaction fastest?

Medium•"Coordination Compounds"

[JEE Mains 2026] Arrange the following metal ions in increasing order of number of unpaired electrons in their low spin octahedral complexes: Mn²⁺, Cr³⁺, Fe²⁺, Co³⁺

Easy•D Block

The electronic configuration of

Cu

(Z=29) is:

Easy•Electrochemistry

The charge required to deposit

1

mole of

Cu

from

CuSO_4

solution is:

Easy•Electrochemistry

Given E°(Zn²⁺/Zn) = -0.76 V and E°(Cu²⁺/Cu) = +0.34 V, the EMF of a Daniell cell is:

Medium•Electrochemistry

For the cell reaction

\text{Zn} + \text{Cu}^{2+} \rightarrow \text{Zn}^{2+} + \text{Cu}

, the standard cell potential is

1.1

V. If

[\text{Zn}^{2+}] = 0.1

M and

[\text{Cu}^{2+}] = 0.01

M at

298

K, the cell potential is (Take

\frac{2.303RT}{F} = 0.059

V):

Easy•Environmental Chemistry

The main cause of ozone layer depletion is:

Easy•Equilibrium

The pH of a

0.001

M HCl solution is:

Medium•Chemical Equilibrium

For the reaction

\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g)

, if

K_p = 1.6 \times 10^{-4}

at a certain temperature, then the value of

K_p

for the reaction

\text{NH}_3(g) \rightleftharpoons \frac{1}{2}\text{N}_2(g) + \frac{3}{2}\text{H}_2(g)

is:

Easy•General

The geometries of the ammonia complexes of

\mathrm{Ni}^{2+}, \mathrm{Pt}^{2+}

and

\mathrm{Zn}^{2+}

, respectively, are

Easy•General

Which of the following combination will produce

\mathrm{H}_{2}

gas?

Easy•General

The green colour produced in the borax bead test of a chromium(III) salt is due to

Easy•General

Calamine, malachite, magnetite and cryolite, respectively, are

Medium•General

Among

[\mathrm{Ni(CO)}_{4}]

[\mathrm{NiCl}_{4}]^{2-}

[\mathrm{Co(NH_3)_{4}Cl_2}]\mathrm{Cl}

\mathrm{Na_3}[\mathrm{CoF_6}]

\mathrm{Na_2O_2}

and

\mathrm{CsO_2}

number of paramagnetic compounds is

Medium•General

On decreasing the

p \mathrm{H}

from 7 to 2, the solubility of a sparingly soluble salt (MX) of a weak acid (HX) increased from

10^{-4} \mathrm{~mol} \mathrm{~L}^{-1}

10^{-3} \mathrm{~mol} \mathrm{~L}^{-1}

. The

p\mathrm{~K}_{\mathrm{a}}

\mathrm{HX}

Medium•General

For the following electrochemical cell at

298 \mathrm{~K}

\mathrm{Pt}(s) \mid \mathrm{H}_{2}(g, 1

bar

)\left|\mathrm{H}^{+}(aq, 1 \mathrm{M}) \| \mathrm{M}^{4+}(aq), \mathrm{M}^{2+}(aq)\right| \operatorname{Pt}(s)

E_{\text {cell }}=0.092 \mathrm{~V}

when

\frac{\left[\mathrm{M}^{2+}(aq)\right]}{\left[M^{4+}(aq)\right]}=10^{x}

. Given :

E_{\mathrm{M}^{4} / \mathrm{M}^{2+}}^{0}=0.151 \mathrm{~V} ; 2.303 \frac{R T}{F}=0.059 \mathrm{~V}

The value of

x

Medium•Haloalkanes

[JEE Mains 2026] Cycloalkene (X) reacts with bromine. During the reaction, 1 mole of cycloalkene consumes 1 mole of Br₂ to form a product (Y). The product (Y) has C:Br atomic ratio of 3:1. What is the percentage of bromine in product (Y)?

Easy•Hydrocarbons

The major product of addition of HBr to propene is:

Easy•Hydrogen

Heavy water is:

Easy•Ionic Equilibrium

[JEE Mains 2026] What volume ratio of decimolar NH₄OH and decimolar NH₄Cl should be mixed to give a buffer solution of pH = 9.25 at 25°C? (Given: pKb of NH₄OH = 4.75)

Medium•Ionic Equilibrium

[JEE Mains 2026] Which of the following is a basic buffer?

Medium•Isomerism

The number of chiral centers in 2-bromo-3-chlorobutane is:

Easy•Chemical Kinetics

For a reaction

A \rightarrow B

, the rate doubles when concentration of

A

is doubled. The order of reaction is:

Easy•Kinetics

Which of the following liberates

\mathrm{O}_{2}

upon hydrolysis?

Hard•Kinetics

Match the reactions (in the given stoichiometry of the reactants) in List-I with one of their products given in List-II and choose the correct option.

\textbf{List-I}

(P)

\mathrm{P}_{2} \mathrm{O}_{3}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow

(Q)

\mathrm{P}_{4}+3 \mathrm{NaOH}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow

(R)

\mathrm{PCl}_{5}+\mathrm{CH}_{3} \mathrm{COOH} \rightarrow

(S)

\mathrm{H}_{3} \mathrm{PO}_{2}+2 \mathrm{H}_{2} \mathrm{O}+4 \mathrm{AgNO}_{3} \rightarrow

\textbf{List-II}

(1)

\mathrm{P}(\mathrm{O})\left(\mathrm{OCH}_{3}\right) \mathrm{Cl}_{2}

(2)

\mathrm{H}_{3} \mathrm{PO}_{3}

(3)

\mathrm{PH}_{3}

(4)

\mathrm{POCl}_{3}

(5)

\mathrm{H}_{3} \mathrm{PO}_{4}

Hard•Kinetics

The reaction of

\mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right]

with freshly prepared

\mathrm{FeSO}_4

solution produces a dark blue precipitate called Turnbull's blue. Reaction of

\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]

with the

\mathrm{FeSO}_4

solution in complete absence of air produces a white precipitate

\mathbf{X}

, which turns blue in air. Mixing the

\mathrm{FeSO}_4

solution with

\mathrm{NaNO}_3

, followed by a slow addition of concentrated

\mathrm{H}_2 \mathrm{SO}_4

through the side of the test tube produces a brown ring. Among the following, the brown ring is due to the formation of

Hard•Kinetics

Match the compounds in LIST-I with the observations in LIST-II, and choose the correct option. LIST-I (I) Aniline (II)

o

-Cresol (III) Cysteine (IV) Caprolactam LIST-II (P) Sodium fusion extract of the compound on boiling with

\mathrm{FeSO}_{4}

, followed by acidification with conc.

\mathrm{H}_{2} \mathrm{SO}_{4}

, gives Prussian blue color. (Q) Sodium fusion extract of the compound on treatment with sodium nitroprusside gives blood red color. (R) Addition of the compound to a saturated solution of

\mathrm{NaHCO}_{3}

results in effervescence. (S) The compound reacts with bromine water to give a white precipitate. (T) Treating the compound with neutral

\mathrm{FeCl}_{3}

solution produces violet color.

Hard•Kinetics

A colorless aqueous solution contains nitrates of two metals,

\mathbf{X}

and

\mathbf{Y}

. When it was added to an aqueous solution of

\mathrm{NaCl}

, a white precipitate was formed. This precipitate was found to be partly soluble in hot water to give a residue

\mathbf{P}

and a solution

\mathbf{Q}

. The residue

\mathbf{P}

was soluble in aq.

\mathrm{NH}_{3}

and also in excess sodium thiosulfate. The hot solution

\mathbf{Q}

gave a yellow precipitate with KI. The metals

\mathbf{X}

and

\mathbf{Y}

, respectively, are

Medium•Chemical Kinetics

The half-life of a first-order reaction is

20

minutes. The time required for

75\%

completion of the reaction is:

Medium•Kinetics

The reaction of

\mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right]

with freshly prepared

\mathrm{FeSO}_4

solution produces a dark blue precipitate called Turnbull's blue. Reaction of

\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]

with the

\mathrm{FeSO}_4

solution in complete absence of air produces a white precipitate

\mathbf{X}

, which turns blue in air. Mixing the

\mathrm{FeSO}_4

solution with

\mathrm{NaNO}_3

, followed by a slow addition of concentrated

\mathrm{H}_2 \mathrm{SO}_4

through the side of the test tube produces a brown ring. Precipitate

\mathbf{X}

Medium•Kinetics

LIST-I contains compounds and LIST-II contains reactions LIST-I (I)

\mathrm{H}_2 \mathrm{O}_2

(II)

\mathrm{Mg}(\mathrm{OH})_2

(III)

\mathrm{BaCl}_2

(IV)

\mathrm{CaCO}_3

LIST-II (P)

\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow

(Q)

\mathrm{BaO}_{2}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow

(R)

\mathrm{Ca}(\mathrm{OH})_{2}+\mathrm{MgCl}_{2} \rightarrow

(S)

\mathrm{BaO}_{2}+\mathrm{HCl} \rightarrow

(T)

\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow

Match each compound in LIST-I with its formation reaction(s) in LIST-II, and choose the correct option\

Medium•Kinetics

The major products obtained from the reactions in List-II are the reactants for the named reactions mentioned in List-I. Match List-I with List-II and choose the correct option.

\textbf{List-I}

(P) Etard reaction (Q) Gattermann reaction (R) Gattermann-Koch reaction (S) Rosenmund reduction

\textbf{List-II}

(1) Acetophenone

\stackrel{\mathrm{Zn}-\mathrm{Hg}, \mathrm{HCl}}{\longrightarrow}

(2) Toluene

\underset{\text{(ii)}\mathrm{SOCl}_{2}}{\stackrel{\text { (i) } \mathrm{KMnO}_{4}, \mathrm{KOH}, \Delta}{\longrightarrow}}

(3) Benzene

\underset{\text { anhyd. } \mathrm{AlCl}_{3}}{\stackrel{\mathrm{CH}_{3} \mathrm{Cl}}{\longrightarrow}}

(4) Aniline

\underset{273-278 \mathrm{~K}}{\stackrel{\mathrm{NaNO}_{2} / \mathrm{HCl}}{\longrightarrow}}

(5) Phenol

\stackrel{\mathrm{Zn}, \Delta}{\longrightarrow}

Medium•Kinetics

The reaction of

\mathrm{HClO}_{3}

with

\mathrm{HCl}

gives a paramagnetic gas, which upon reaction with

\mathrm{O}_{3}

produces

Medium•Kinetics

The reaction of

\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}

and

\mathrm{NaCl}

in water produces a precipitate that dissolves upon the addition of

\mathrm{HCl}

of appropriate concentration. The dissolution of the precipitate is due to the formation of

Easy•Metallurgy

Aluminium is extracted from bauxite by:

Easy•Mole Concept

The number of moles in

9

g of water is:

Easy•Organic Chemistry

The IUPAC name of the compound

\text{CH}_3\text{-CH}(\text{OH})\text{-CH}_2\text{-CH}(\text{CH}_3)\text{-CHO}

is:

Easy•Organic Chemistry

The functional group present in

CH_3CHO

is:

Easy•Organic Chemistry

The IUPAC name of the compound (CH₃)₃C-CH₂-CH₃ is:

Easy•Organic

On complete hydrogenation, natural rubber produces

Medium•Organic Chemistry

[JEE Mains 2026] Which of the following is the correct order of reactivity of the given nucleophiles when treated with CH₃Br in methanol? I. CH₃O⁻ II. CH₃S⁻ III. CH₃Se⁻ IV. Cl⁻

Easy•P Block

[JEE Mains 2026] An element of p-block forms a species of type EH₄⁺, which when passed through a basic solution of K₂[HgI₄], forms a brown precipitate. Which element is E and what is the name of the test?

Easy•P-Block Elements

Which noble gas is used in filling weather balloons?

Easy•P Block

Which halogen has the highest electron affinity?

Medium•P Block

[JEE Mains 2026] Two elements of p-block can form halides XF₅ and YF₃. XF₅ can act as a Lewis acid while YF₃ can act as a Lewis base. What is the hybridization of 'X' in XF₅ and 'Y' in YF₃ respectively?

Easy•Periodic Table

Which of the following has the smallest atomic radius?

Easy•Periodic Table

[JEE Mains 2026] What is the correct order of first ionization enthalpy?

Easy•Periodic Table

Among halogens, the element with the highest electron affinity is:

Medium•Periodic Table

[JEE Mains 2026] What is the correct order of electron gain enthalpy (considering magnitude only) for Group 16 elements?

Easy•Periodic Table

[JEE Mains 2026] Four elements from the second period (Boron to Oxygen) have the following first ionization energy values (in kJ/mol): 1086.5, 800.6, 1313.9, 1402.3. What is the first ionization energy value for Nitrogen?

Easy•Polymers

Nylon-6,6 is an example of:

Easy•Practical Chemistry

Sodium imparts which color to the flame?

Easy•Redox Reactions

The oxidation state of Cr in

K_2Cr_2O_7

is:

Easy•S Block

Which alkali metal does not form a stable superoxide?

Easy•Thermodynamics

For an exothermic reaction at constant pressure, which of the following is true?

Medium•Solid State

The packing efficiency of a body-centered cubic (BCC) unit cell is approximately:

Easy•Solutions

The molarity of a solution containing

4

g of NaOH in

500

mL solution is (Molar mass of NaOH =

40

g/mol):

Easy•Solutions

The osmotic pressure of a solution containing

6

g of urea (molar mass =

60

g/mol) in

500

mL of solution at

27°

C is (R =

0.082

L·atm/mol·K):

Easy•Solutions

The boiling point elevation of a solution containing 3 g of urea (molar mass = 60 g/mol) in 100 g of water is: (Kb for water = 0.52 K kg/mol)

Medium•Solutions

The reagent(s) that can selectively precipitate

\mathrm{S}^{2-}

from a mixture of

\mathrm{S}^{2-}

and

\mathrm{SO}_{4}^{2-}

in aqueous solution is(are)

Medium•Solutions

[JEE Mains 2026] Statement-I: The Henry's law constant (Kₕ) for an ideal dilute solution does not change with varying the concentration of solute at a given temperature. Statement-II: For a solution having the same gas as solute, Kₕ is independent of the nature of the solvent. Which of the following is correct?

Medium•Solutions

[JEE Mains 2026] 100 g of 98% (by weight) H₂SO₄ is mixed with 100 g of 49% (by weight) H₂SO₄. What is the mole fraction of H₂SO₄ in the resulting solution?

Medium•Solutions

For the following cell,

\mathrm{Zn}(s)\left|\mathrm{ZnSO}_{4}(a q) \| \mathrm{CuSO}_{4}(a q)\right| \mathrm{Cu}(s)

when the concentration of

\mathrm{Zn}^{2+}

is 10 times the concentration of

\mathrm{Cu}^{2+}

, the expression for

\Delta G\left(\right.

\left.\mathrm{J} \mathrm{mol}^{-1}\right)

is [

\mathrm{F}

is Faraday constant;

\mathrm{R}

is gas constant;

\mathrm{T}

is temperature;

E^{o}(

cell

)=1.1 \mathrm{~V}

]

Medium•Solutions

Plotting

1 / \Lambda_{\mathrm{m}}

against

\mathrm{c} \Lambda_{\mathrm{m}}

for aqueous solutions of a monobasic weak acid (HX) resulted in a straight line with y-axis intercept of

\mathrm{P}

and slope of

\mathrm{S}

. The ratio

\mathrm{P} / \mathrm{S}

\left[\Lambda_{\mathrm{m}}=\right.

molar conductivity

\Lambda_{\mathrm{m}}^{\mathrm{o}}=

limiting molar conductivity

\mathrm{c}=

molar concentration

\mathrm{K}_{\mathrm{a}}=

dissociation constant of

\mathrm{HX}

]

Easy•States Of Matter

At STP, the volume occupied by

2

moles of an ideal gas is:

Easy•Surface Chemistry

Physical adsorption is characterized by:

Easy•Thermodynamics

In an isothermal expansion of an ideal gas, 500 J of heat is absorbed by the system. The work done by the gas is:

Easy•Thermodynamics

The enthalpy of combustion of methane is

-890

kJ/mol. If

8

g of methane is completely burnt, the heat released is (Molar mass of CH₄ = 16 g/mol):

Medium•Thermodynamics

Given the following thermochemical equations: - C(s) + O₂(g) → CO₂(g); ΔH₁ = -393 kJ/mol - CO(g) + ½O₂(g) → CO₂(g); ΔH₂ = -283 kJ/mol The enthalpy of formation of CO(g) is:

Medium•Thermodynamics

For a reaction to be spontaneous at all temperatures, which of the following conditions must be satisfied?

Easy•Thermodynamics

Two moles of an ideal gas undergo a reversible isothermal expansion at 300 K, where the volume increases from 10 L to 20 L. The work done by the gas is (R = 8.314 J/mol·K, ln 2 = 0.693):

Easy•Thermodynamics

For vaporization of

1

mole of water at

100°C

and

1

atm, if

\Delta H_{vap} = 40.7

kJ/mol, the entropy change is:

Hard•Thermodynamics

The standard state Gibbs free energies of formation of

\mathrm{C}

(graphite) and

C

(diamond) at

\mathrm{T}=298 \mathrm{~K}

are

\begin{gathered} \Delta_{f} G^{o}[\mathrm{C}(\text { graphite })]=0 \mathrm{~kJ} \mathrm{~mol} \\ \Delta_{f} G^{o}[\mathrm{C}(\text { diamond })]=2.9 \mathrm{~kJ} \mathrm{~mol}^{-1} . \end{gathered}

The standard state means that the pressure should be 1 bar, and substance should be pure at a given temperature. The conversion of graphite [ C(graphite)] to diamond [ C(diamond)] reduces its volume by

2 \times 10^{-6} \mathrm{~m}^{3} \mathrm{~mol}^{-1}

. If

\mathrm{C}

(graphite) is converted to

\mathrm{C}

(diamond) isothermally at

\mathrm{T}=298 \mathrm{~K}

, the pressure at which

\mathrm{C}

(graphite) is in equilibrium with

\mathrm{C}(

diamond), is [Useful information:

1 \mathrm{~J}=1 \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-2} ; 1 \mathrm{~Pa}=1 \mathrm{~kg} \mathrm{~m}^{-1} \mathrm{~s}^{-2} ; 1

bar

=10^{5} \mathrm{~Pa}

]

Medium•Thermodynamics

Using the bond enthalpies: C-H =

414

kJ/mol, C-C =

347

kJ/mol, C=C =

611

kJ/mol, H-H =

435

kJ/mol. The enthalpy change for the hydrogenation of ethene (

\text{C}_2\text{H}_4 + \text{H}_2 \rightarrow \text{C}_2\text{H}_6

) is:

Medium•Thermodynamics

One mole of an ideal gas at

300 \mathrm{~K}

in thermal contact with surroundings expands isothermally from

1.0 \mathrm{~L}

2.0 \mathrm{~L}

against a constant pressure of

3.0 \mathrm{~atm}

. In this process, the change in entropy of surroundings

\left(\Delta S_{\text {surr }}\right)

\mathrm{J} \mathrm{K}^{-1}

is (1

\mathrm{L} \operatorname{atm}=101.3 \mathrm{~J})

Medium•Thermodynamics

One mole of an ideal monoatomic gas at 300 K expands irreversibly and isothermally from 10 L to 20 L against a constant external pressure of 1 atm. The entropy change of the universe is (R = 8.314 J/mol·K, ln 2 = 0.693, 1 L·atm = 101.3 J):

Medium•Thermodynamics

One mole of an ideal monoatomic gas (γ = 5/3) undergoes a reversible adiabatic expansion from initial temperature 400 K and volume 2 L to final volume 16 L. The final temperature of the gas is: