Science (English Medium) Class 12 - CBSE Important Questions

Write the structure of main compounds A and B in the following reaction:

\[\ce{CH3CH2CN->[CH3MgBRH/3O+]A->[LiAIH4]B}\]

Why phenol undergoes electrophilic substitution more easily than benzene?

Account for the following:
o-nitrophenol is more steam volatile than p-nitrophenol.

Write the reaction involved in the following:
Friedal-Crafts Alkylation of Phenol

Give simple chemical test to distinguish between Ethanol and Phenol.

Give reasons for the following:

Sulphur in vapour state shows paramagnetic behaviour.

Give reasons for the following:
Ozone is thermodynamically less stable than oxygen.

Write the name of gas released when Cu is added to
dilute HNO₃

Write the name of gas released when Cu is added to
conc. HNO₃

Arrange the following in the increasing order of their property indicated:

Benzoic acid, Phenol, Picric acid, Salicylic acid (pka values).

Arrange the following in the increasing order of their property indicated:

ethanol, ethanoic acid, benzoic acid (boiling point)

Convert the following:

Phenol to N-phenylethanamide.

Convert the following: 

Propanenitrile to ethanol.

What happens when reactions:

N-ethylethanamine reacts with benzenesulphonyl chloride.

What happens when reactions:

Benzylchloride is treated with ammonia followed by the reaction with Chloromethane.

The major product of acid catalysed dehydration of 1-methylcyclohexanol is ______.

Given below are two statements labelled as Assertion (A) and Reason (R).

Assertion (A): An ether is more volatile than an alcohol of comparable molecular mass

Reason (R): Ethers are polar in nature.

Select the most appropriate answer from the options given below:

Name the suitable alcohol and reagent, from which 2-Chloro-2-methyl propane can be prepared.

Write the equations for the following reaction:

Tert butyl chloride is treated with sodium ethoxide.

Write the equations for the following reaction:

Phenol is treated with chloroform in the presence of NaOH