List of top Chemistry Questions asked in CBSE CLASS XII

Assertion (A): p-Nitroaniline is a weaker base than p-toluidine. Reason (R): The electron-withdrawing effect of \(-NO_2\) group in p-nitroaniline makes it a weaker base.
Assertion (A): Uracil base is present in DNA. Reason (R): DNA undergoes self-replication.
The addition of a catalyst during a chemical reaction alters which of the following quantities of the reaction?
For the elementary reaction \( P \to Q \), the rate of disappearance of ‘P’ increases by a factor of 8 upon doubling the concentration of ‘P’. The order of the reaction with respect to ‘P’ is:
An azeotropic solution of two liquids has a boiling point lower than either of them when it:
The relative lowering of vapor pressure of an aqueous solution containing a non-volatile solute is 0.0225. The mole fraction of the non-volatile solute is:
Ethanol on heating with conc. H\(_2\)SO\(_4\) at 413 K gives:
Assertion (A): Aliphatic primary amines can be prepared by Gabriel phthalimide synthesis. Reason (R): Alkyl halides undergo nucleophilic substitution with anion formed by phthalimide.
During electrolysis of an aqueous solution of NaCl:
Which of the following ligands forms a chelate complex?
Anisole reacts with HI to give:
Which of the following contains sp\(^2\) hybridized carbon bonded to X?
Which of the following is most acidic?
Ligand EDTA\(^{4-}\) is an example of a:
When MnO\(_2\) is fused with KOH in air, it gives:
In the Arrhenius equation, when log k is plotted against 1/T, a straight line is obtained whose:
Assertion (A): When NaCl is added to water, a depression in freezing point is observed.
Reason (R): NaCl undergoes dissociation in water.
Which functional groups of glucose interact to form cyclic hemiacetal leading to pyranose structure?
For an electrolyte undergoing association in a solvent, the van’t Hoff factor:
Acetic acid reacts with PCl5to give:
The formation of cyanohydrin from an aldehyde is an example of:
The reaction of an alkyl halide with sodium alkoxide forming ether is known as:
The correct order of the ease of dehydration of the following alcohols by the action of conc. H2SO4 is:
Assertion (A): The pKa} of ethanoic acid is lower than that of C1} – CH2} – COOH.
Reason (R): Chlorine shows electron withdrawing (–I) effect which increases the acidic character of C1} – CH2} – COOH.
Assertion (A): Aniline is a stronger base than ammonia.
Reason (R): The unshared electron pair on nitrogen atom in aniline becomes less available for protonation due to resonance.