List of top Questions asked in CBSE CLASS XII- 2026

Draw the structure of the major product in the following reaction: \( CH_{3}CH = C(CH_{3})_{2} + HBr \rightarrow \)

Draw the structure of the major product in the following reaction:

Write the structures of A, B and C in the following reaction:

Write the structures of A, B and C in the following reaction:

Write IUPAC name of the following compound : \( [Cr(NH_{3})_{4} (ONO)Cl] NO_{3} \)

Write IUPAC name of the following compound : \( Na[Ag(CN)_{2}] \)

State the condition under which a bimolecular reaction may be kinetically a first order reaction.

What are the hydrolysis products of the following ? Lactose

Explain the following with the help of Henry’s law : (i) Bends (ii) Anoxia

What are the hydrolysis products of the following ? DNA containing Thymine

Assertion (A) : For complex reaction, order of reaction is given by the slowest step.
Reason (R) : Order of a reaction is an experimental quantity.

Reactions of which order will show the rate to be independent of the concentration of the reactant ? Give one example of this order.

Assertion (A) : \( E^{\circ}_{Sc^{3+}/Sc^{2+}} \) has low value.
Reason (R) : Because of the stability of \( Sc^{3+} \) ion which has a noble gas configuration.

Assertion (A) : Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
Reason (R) : Diazonium salts of aliphatic amines undergo resonance.

Assertion (A) : Alcohols act as Bronsted bases as well as Bronsted acids.
Reason (R) : It is due to the presence of unshared electron pairs on oxygen atom and presence of polar \( O - H \) bond.

When a liquid and its vapour are at equilibrium and the pressure is suddenly decreased :

The rate of a first order reaction is \( 5.6 \times 10^{-4} \, mol \, L^{-1} \, s^{-1} \), when the concentration of reactant is \( 0.2 \, mol \, L^{-1} \). The rate constant \( 'k' \) is :

Consider the following cell at \( 298 \, K \): \( Mg (s) \mid Mg^{2+} (1.0 \, M) \parallel Cu^{2+} (1.0 \, M) \mid Cu (s) \). How can we increase the emf of the cell using the same substances ?

Nucleic acids are polymers of :

In the reaction of \( NaOBr \) with amide, the carbonyl carbon is lost as :

The chelating ligand used for the treatment of lead poisoning is :

The correct order of decreasing basicities of \( C_{2}H_{5}NH_{2} \), \( (C_{2}H_{5})_{2}NH \) and \( (C_{2}H_{5})_{3}N \) in aqueous solution is :

Manganate ion is paramagnetic due to the presence of :

The boiling point of one molal \( NaCl \) solution, assuming \( NaCl \) to be completely dissociated in water is : (\( K_{b} \) for water = \( 0.52 \, K \, kg \, mol^{-1} \))

Lucas reagent produces cloudiness immediately with :