WB JEE 2026

The major products U and V in the following reaction are

In the following sequence of reactions, what is the end product ' $Z$ '?

Which one of the following does not lose water even in conc. $\mathrm{H}_2 \mathrm{SO}_4$ ?

The products $\mathbf{X}$ and $\mathbf{Y}$ in the following reaction sequence are

The mass of an electron is $9 \cdot 1 \times 10^{-31} \mathrm{~kg}$ ．If its K ．E．is $3 \cdot 0 \times 10^{-25} \mathrm{~J}$ ，its wavelength is（approximately）

The plot of radial probability density（ $4 \pi r^2 R^2$ ）against $r$ for an electron in $n p$ orbital of a many electron atom is given below．

The value of $n$ is

Which of the following statement(s) is/are correct about the given compound?

The increasing order of basicity of the following compounds is

Peroxide ion is

Among $\mathrm{N}_2 \mathrm{O}, \mathrm{ClF}_2^{-}, \mathrm{SO}_2$ and $\mathrm{I}_3^{+}$, the species having the linear structures are

In which of the following species, $\mathrm{sp}^3 \mathrm{~d}^2$ hybridisation is not associated?

For the reaction $A \rightarrow B$ ，variation of concentration is plotted against time as shown below．

Which of the following statements is true？

An organic compound undergoes first order decomposition．The time taken for its decomposition to $\frac{1}{8}$ th and $\frac{1}{10}$ th of its initial concentration are $t_{1 / 8}$ and $t_{1 / 10}$ respectively．The value of $\left[\frac{t_{1...

In a first order reaction，the concentration of reactant decreases from 400 moles lit $^{-1}$ to 50 moles lit ${ }^{-1}$ in $7 \cdot 5 \times 10^3 \mathrm{~s}$ ．The rate constant of the reaction is（approximately）

The correct order of conductivity of $0.001(\mathrm{M})$ separate aqueous solutions of $\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Cl}_4(\mathrm{i})$; $\left[\mathrm{Cr}\left(\mathrm{NH}_3\right)_6\right] \mathrm{Cl}_3$ (i...

For the metal complex $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{SO}_4\right] \mathrm{Br}$ ，coordination number，oxidation number，number of $d$－electrons and number of unpaired $d$－electrons are respectively

Which of the following have tetrahedral structures？

The calculated magnetic moment for low spin $[\operatorname{Ru}(E D T A)]^{-}$is

In a conductance experiment, aqueous $\mathrm{AgNO}_3$ solution is added to aqueous KCl solution gradually and simultaneously the molar conductivity ( $\lambda_{\mathrm{m}}$ ) is measured. The correct plot of $\lambda_{\mathrm{m}}$ versus v...

The van der Waal's equation : $\left(P+\frac{a}{4 V^2}\right)\left(V-\frac{b}{2}\right)=\frac{R T}{2}$ is valid for

Which of the following plot(s) is/are correct representation(s) of Boyle's Law?

Rank the following anions in order of decreasing nucleophilicity in a polar protic solvent (most → least nucleophilic).

The major product in the following reaction is

Indicate the major product of the following reaction:

\(\mathrm{RO}-\mathrm{CH}_2-\mathrm{C} \equiv \mathrm{CH} \xrightarrow{\mathrm{X}} \xrightarrow{\mathrm{Y}} \mathrm{RO}^{-} \mathrm{CH}_2-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_2 \mathrm{CH}_2-\mathrm{Br}\)

To carry out the above conve...

In the following reaction sequence, the product Y is
$$ \mathrm{Br}\left(\mathrm{CH}_2\right)_{12}-\mathrm{C} \equiv \mathrm{CH} \xrightarrow{\mathrm{NaNH}_2} \mathrm{X} \xrightarrow[\text { catalyst }]{\mathrm{H}_2, \text { Lindler }} \ma...

A buffer solution contains 100 ml of $0.01(\mathrm{M}) \mathrm{CH}_3 \mathrm{COOH}$ and 200 ml of $0.02(\mathrm{M}) \mathrm{CH}_3 \mathrm{COONa}_a .700 \mathrm{ml}$ of water is added subsequently to the buffer solution．The pH before and aft...

How many isomers can a compound with molecular formula $\mathrm{C}_3 \mathrm{H}_5 \mathrm{Br}$ have？

Glucose is added to 1 litre of water to such an extent that $\Delta T_f / K_f$ equals to $\frac{1}{1000}$ ．The weight of glucose added is

The van't Hoff Factor (i) for a dilute aqueous solution of $\mathrm{Na}_2 \mathrm{SO}_4$ is

Which of the following statement（s）is／are correct？

Which one of the following cations gives a chocolate brown precipitate upon addition of aqueous solution of $\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]$ ？

A compound $(\mathrm{X})$ when treated with $\mathrm{CuSO}_4$ solution yields a brown precipitate．On adding hypo solution the precipitate turns white．The compound $(\mathrm{X})$ is

A $5.0 \mathrm{~cm}^3$ solution of $\mathrm{H}_2 \mathrm{O}_2$ liberates 1.27 g of iodine from an acidified KI solution. The percentage strength of $\mathrm{H}_2 \mathrm{O}_2$ is close to

A compound contains two types of atoms $A$ and $B$ ．Its crystal structure is a cubic lattice with＇$A$＇ atoms at the corner of the unit cells and＇$B$＇atoms at the body centres．The simplest formula of the compound will be

Borazole is prepared by heating the product isolated by reacting

Which of the following is the structure of pyrosulphuric acid?

Three engines $\mathrm{A}, \mathrm{B}$ and C take steam at $130^{\circ} \mathrm{C}$ and reject it at $20^{\circ} \mathrm{C}, 40^{\circ} \mathrm{C}$ and $50^{\circ} \mathrm{C}$ respectively．The most efficient engine will be

1 mole of an ideal gas undergoes the following processes：
Process $A \rightarrow$ Isothermal expansion at 400 K from volume $\mathrm{V}_1$ to volume $\mathrm{V}_2$ ，such that $\mathrm{V}_2=4 \mathrm{~V}_1$
Process $B \rightarrow$ Adiabatic...