List of top Questions asked in WBJEE

Number of moles of ions produced by the complete dissociation of one mole of Mohr’s salt in water is:

How many P–O–Plinkages are there in P₄O₁₀?

Which of the following species exhibits both LMCT and paramagnetism?

What will be the change in acidity if:
(i) CuSO₄ is added to saturated (NH₄)₂SO₄ solution,
(ii) SbF₅ is added to anhydrous HF?

Q and R in the reaction sequences are respectively:

For a first-order reaction with rate constant k, the slope of the plot of log(reactant concentration) against time is:

Which hydrogen-like species will have the same radius as the 1st Bohr orbit of a hydrogen atom?

After the emission of a β-particle followed by an α-particle from \(^{214}_{83}\text{Bi}\), the number of neutrons in the atom is:

The correct order of boiling points of the given aqueous solutions is

Which of the following statements is true about the equilibrium constant and rate constant of a single-step chemical reaction?

Equal volumes of aqueous solution of 0.1 M HCl and 0.2 M H₂SO₄ are mixed. The concentration of H+ ions in the resulting solution is:

Identify the incorrect statement among the following:

Which of the following statements is correct for a spontaneous polymerization reaction?

Consider an electron moving in the first Bohr orbit of a He\(^+\) ion with velocity \(v_1\). If it is allowed to move in the third Bohr orbit with velocity \(v_3\), determine the correct \(v_3 : v_1\) ratio.\\

At \(25^\circ \text{C}\), the ionic product of water is \(10^{-14}\). The free energy change (\(\Delta G^\circ\)) for the self-ionization of water in kcal mol\(^{-1}\) is:

The compressibility factor for a van der Waals gas at high pressure is

For a spontaneous process, the incorrect statement is:

The major product of the following reaction is:

The correct acidity order of phenol (I), 4-hydroxybenzaldehyde (II), and 3-hydroxybenzaldehyde (III) is:

The compound that does not give a positive test for nitrogen in Lassaigne’s test is

The compounds A and B are respectively:

The product ’P’ in the above reaction is:

The decreasing order of reactivity of the following alkenes towards HBr addition is: \(\text{CH}_3-\text{CH}=\text{CH}_2 \, (\text{I}), \quad \text{CF}_3-\text{CH}=\text{CH}_2 \, (\text{II}), \quad \text{MeOCH}=\text{CH}_2 \, (\text{III}),\) , \((\text{IV}) \)

Toluene reacts with mixed acid at 25°C to produce:

The reactivity order of the following molecules towards SN1 reaction is:
Allyl chloride (I), Chlorobenzene (II), Ethyl chloride (III)