List of top Questions asked in JEE Main- 2026

Consider the following gas phase reaction being carried out in a closed vessel at 25°C: \[ 2A(g) \longrightarrow 4B(g) + C(g) \] The total pressure of the system at different time intervals is given as:

We need to find the pressure of \( C(g) \) at the 30 minutes time interval.}

Let [·] denote the greatest integer function. If the domain of the function \[ f(x) = \cos^{-1}\left(\frac{4x + 2\lfloor x \rfloor}{3}\right) \] is \([\alpha, \beta]\), then \(12(\alpha + \beta)\) is equal to:

Consider the following reactions sequence:

When the product (P) is subjected to Carius analysis using \( \text{AgNO}_3 \), 1.0 g of the product (P) will produce _______ g of the precipitate of \( \text{AgBr} \). (Nearest integer)}

Number of paramagnetic ions among the following d- and f-block metal ions is _______.} \[ \text{Mn}^{2+}, \, \text{Cu}^{2+}, \, \text{Zn}^{2+}, \, \text{Yb}^{2+}, \, \text{Sc}^{3+}, \, \text{La}^{3+}, \, \text{Gd}^{3+}, \, \text{Lu}^{3+}, \, \text{Ti}^{4+}, \, \text{Ce}^{4+} \] \text{(Atomic number of Mn = 25, Cu = 29, Zn = 30, Yb = 70, Sc = 21, La = 57, Gd = 64, Lu = 71, Ti = 22, Ce = 58)}

Consider the following two half-cell reactions along with the standard reduction potential given: \[ \text{CO}_2 + 6H^+ + 6e^- \rightarrow \text{CH}_3\text{OH} + \text{H}_2\text{O} \quad E^\circ_{\text{red}} = 0.02 \, \text{V} \] \[ \frac{1}{2} \text{O}_2 + 2H^+ + 2e^- \rightarrow \text{H}_2\text{O} \quad E^\circ_{\text{red}} = 1.23 \, \text{V} \] A fuel cell was set up using the above two reactions such that the cell operates under the standard condition of 1 bar pressure and 298 K temperature. The fuel cell works with 80% efficiency. If the work derived from the cell using 1 mol of CH\(_3\)OH is used to compress an ideal gas isothermally against a constant pressure of 1 kPa, then the change in the volume of the gas, \( \Delta V = \) _______ m\(^3\) (nearest integer).}

An organic compound "x" where molar ratio of C, O and H are equal, on treatment with 50% KOH under reflux followed by acidification produced "y". The most likely structure of "y" is: Options

A molecule \( (X) \) with the following structure under mild acidic conditions is hydrolyzed to produce \( (Y) \) and \( (Z) \). Identify the correct statements about \( (Y) \) and \( (Z) \).}

Among \( \text{Fe}^{2+}, \text{Fe}^{3+}, \text{Cr}^{2+} \) and \( \text{Zn}^{2+} \), the ion that shows positive borax bead test and with highest ionisation enthalpy is:

The surface of sodium metal is irradiated with radiation of wavelength \( x \) nm. The kinetic energy of ejected electrons is \( 2.8 \times 10^{-20} \) J. The work function of sodium is 2.3 eV. The value of \( x \) is _______ \( \times 10^2 \) nm. (Nearest integer)}

Identify the correct pair having amino acid (A) and the hormone (B) that is iodinated derivative of the amino acid (A).} Choose the correct answer from the options given below:

Correct statements regarding alkyl halides (R–X) among the following are:

• Alcohol being less polar solvent as compared to water, alcoholic KOH favours elimination reaction with R–X.
• Order of reactivity towards $S_N1$ mechanism is $C_6H_5-CH_2-Cl>C_6H_5-CHCl-C_6H_5$.
• Non-substituted aryl halides exhibit properties similar to alkyl halides.
• Vinyl chloride is an example of haloalkene and allyl chloride is an example of haloalkyne.
• $R-Cl$ can be prepared by reacting $R-OH$ with $SOCl_2$ but $Ar-OH$ cannot be prepared by reacting $Ar-OH$ with $SOCl_2$.

Complete combustion of \( X \) g of an organic compound gave 0.25 g of CO\(_2\) and 0.12 g of H\(_2\)O. If the percent of carbon is 25% and of hydrogen is 4.8%, then \( X = \) _______ g (Nearest integer).}

The compound \( X \) on:

• (i) On heating in the presence of anhydrous \( \text{AlCl}_3 \) and \( \text{HCl} \) gas gives 2,4-dimethyl pentane.
• (ii) Aromatization gives toluene and
• (iii) Cyclisation gives methyl cyclohexane.

The correct name of compound \( X \) is:

Given below are two statements:
Statement I: In

, the carbocation is stabilized by the \( +R \) effect of the \( \text{OCH}_3 \) group.
Statement II:In

, the carbanion is stabilized by the \( -R \) effect of the \( \text{NO}_2 \) group.
In light of the above statements, choose the correct answer from the options given below:

Given below are two statements: Statement I: Among Zn, Mn, Sc and Cu, the energy required to remove the third valence electron is highest for Zn and lowest for Sc.
Statement II: The correct order of the following complexes in terms of CFSE is [Co(H₂O)₆]²⁺<[Co(H₂O)₆]³⁺<[Co(en)₃]³⁺.
In light of the above statements, choose the correct answer from the options given below:

Which of the following complexes will show coordination isomerism?} (A) \( [\text{Ag}(\text{NH}_3)_2][\text{Ag}(\text{CN})_2] \)
(B) \( [\text{Co}(\text{NH}_3)_6][\text{Cr}(\text{CN})_6] \)
(C) \( [\text{Co}(\text{NH}_3)_6][\text{Co}(\text{CN})_6] \)
(D) \( [\text{Fe}(\text{NH}_3)_6][\text{Co}(\text{CN})_6] \)
(E) \( [\text{Co}(\text{NH}_3)_6][\text{Fe}(\text{CN})_6] \) Choose the correct answer from the options given below:

The correct set that contains all kinds (basic, acidic, amphoteric and neutral) of oxides is:

Consider the reaction \( aX \rightarrow bY \), for which the rate constant at 30°C is \( 1 \times 10^{-3} \, \text{mol}^{-1} \, \text{L} \, \text{s}^{-1} \). Which of the following statements are true?}

• (A) When concentration of \( X \) is increased to four times, the rate of reaction becomes 16 times.
• (B) The reaction is a second order reaction.
• (C) The half-life period is independent of the concentration of \( X \).
• (D) Decomposition of \( \text{N}_2\text{O}_5 \) is an example of the above reaction.
• (E)

  

  is valid for the reaction

Choose the correct answer from the options given below:

Given below are two statements: Statement I: The second ionization enthalpy of B, Al and Ga is in the order of B>Al>Ga.
Statement II: The correct order in terms of first ionization enthalpy is Si<Ge<Pb<Sn.
In light of the above statements, choose the correct answer from the options given below:

At 25°C, 20.0 mL of 0.2 M weak monoprotic acid HX is titrated against 0.2 M NaOH. The pH of the solution (a) at the start of the titration (when NaOH has not been added) and (b) when 10 mL of NaOH is added respectively are:

Gas ‘A’ undergoes change from state ‘X’ to state ‘Y’. In this process, the heat absorbed and work done by the gas is 10 J and 18 J respectively. Now gas is brought back to state ‘X’ by another process during which 6 J of heat is evolved. In the reverse process of ‘Y’ to ‘X’, the work done is:

If sunlight is focused on a paper using a convex lens, it starts burning the paper in the shortest time when the lens is kept at 30 cm above the paper. If the radius of curvature of the lens is 60 cm, then the refractive index of the lens material is \( \frac{\alpha}{10} \). The value of \( \alpha \) is _______.

5 moles of unknown gas is heated at constant volume from 10°C to 20°C. The molar specific heat of this gas at constant pressure \( c_p = 8 \) cal/mol·°C and \( R = 8.36 \) J/mol·°C. The change in the internal energy of the gas is _______ calorie.}

The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1. It has two carbon atoms. The weight (in g) of CO2(g) formed when 3.38 g of this hydrocarbon is completely burnt in oxygen is: (Given: Molar mass in g mol\(^{-1}\): C: 12, H: 1, O: 16)}

Moment of inertia about an axis \( AB \) for a rod of mass 40 kg and length 3 m is same as that of a solid sphere of mass 10 kg and radius \( R \) about an axis parallel to \( AB \) axis with separation of 3 m as shown in the figure below. The value of \( R \) is given as \( \sqrt{\frac{\alpha}{2}} \). The value of \( \alpha \) is _______.