List of top Questions asked in CBSE CLASS XII

In the Arrhenius equation \( k = Ae^{-E_a/RT} \), ‘A’ represents:
Which of the following represents the fraction of molecules with energies equal to or greater than E$_a$?
Out of 2-Bromobutane, 1-Bromobutane, 2-Bromopropane and 1-Bromopropane, the molecule which is chiral in nature is:
In the given reaction sequence, the structure of Y would be:
aniline (C6H5NH2)
Assertion (A): Acetanilide is less basic than aniline.
Reason (R): Acetylation of aniline results in decrease of electron density on nitrogen.
Williamson synthesis of preparing unsymmetrical ether is:
Which one of the following amines gives an alcohol on reaction with HNO₂?
Assertion (A): Boiling point of (CH₃)₃N is higher than that of CH₃CH₂CH₂NH₂.
Reason (R): Hydrogen bonding is more extensive in CH₃CH₂CH₂NH₂.
Which by-product is obtained in the manufacture of phenol from cumene ?
The reagent that can be used to convert benzenediazonium chloride to benzene is:
Assertion (A): The solubility of aldehydes and ketones in water decreases with increase in size of the alkyl group.
Reason (R): Aldehydes and ketones have dipole-dipole interaction.
The conversion of phenol to salicylic acid can be accomplished by

Alkyl halides undergoing nucleophilic bimolecular substitution reaction involve: 

Which is the correct IUPAC name for
$\text{CH}_3$
Alkenes are formed by heating alcohols with conc. H$_2$SO$_4$. The first step in the reaction is:
Assertion (A): n-Butyl chloride has higher boiling point than n-Butyl bromide.
Reason (R): C—Cl bond is more polar than C—Br bond.
Hofmann Bromamide degradation reaction is given by:
Assertion (A): Hydrolysis of an ester follows first order kinetics.
Reason (R): The concentration of water does not get altered much during the reaction.
Which reagents are required for one step conversion of chlorobenzene to toluene?
Which of the following compounds would be hydrolyzed by aqueous KOH most easily?
In the Hinsberg method for separation of primary, secondary, and tertiary amines, the reagent used is:
Pyranose ring of glucose is formed due to the reaction between:
Assertion (A): Phenol is strongly acidic as compared to ethanol.
Reason (R): Phenoxide ion is more stable than ethoxide ion.
The gas evolved when methylamine reacts with HNO\textsubscript{2 is:}
CH3CH2CHO and CH3CH2COOH can be distinguished by: