Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Chloromethane on treatment with excess of ammonia yields mainly ______.

Why iodoform has appreciable antiseptic property?

Name the alkene which will yield 1-chloro-1-methylcyclohexane by its reaction with \[\ce{HCl}\]. Write the reactions involved.

Diphenyls are potential threat to the environment. How are these produced from arylhalides?

What are the IUPAC names of the insecticide DDT and benzene hexachloride? Why is their use banned in India and other countries?

How will you obtain monobromobenzene from aniline?

How can you obtain iodoethane from ethanol when no other iodine-containing reagent except NaI is available in the laboratory?

Match the compounds given in Column I with the effects given in Column II.

Assertion: It is difficult to replace chlorine by –OH in chlorobenzene in comparison to that in chloroethane.

Reason: Chlorine-carbon \[\ce{(C - Cl)}\] bond in chlorobenzene has a partial double bond character due to resonance.

Some halogen containing compounds are useful in daily life. Some compounds of this class are responsible for exposure of flora and fauna to more and more of UV light which causes destruction to a great extent. Name the class of these halocompounds. In your opinion, what should be done to minimise harmful effects of these compounds.

The reagent which does not react with both, acetone and benzaldehyde.

Which is the most suitable reagent for the following conversion?

\[\begin{array}{cc}
\phantom{....................}\ce{O}\phantom{.....................................}\ce{O}\phantom{.}\\
\phantom{....................}||\phantom{......................................}||\phantom{.}\\
\phantom{}\ce{CH3 - CH = CH - CH2 - C - CH3 -> CH3 - CH = CH - CH2 - C - OH}\phantom{.}
\end{array}\]

Through which of the following reactions number of carbon atoms can be increased in the chain?

(i) Grignard reaction

(ii) Cannizaro’s reaction

(iii) Aldol condensation

(iv) HVZ reaction

Match the reactions given in Column I with the suitable reagents given in Column II.

Assertion: Aldehydes and ketones, both react with Tollen’s reagent to form silver mirror.

Reason: Both, aldehydes and ketones contain a carbonyl group.

Arenium ion involved in the bromination of aniline is:

(i)

(ii)

(iii)

(iv)

Why is benzene diazonium chloride not stored and is used immediately after its preparation?

Why does acetylation of –NH₂ group of aniline reduce its activating effect?

Predict the product of reaction of aniline with bromine in non-polar solvent such as \[\ce{CS2}\].

Why is aniline soluble in aqueous HCl?