Chemistry NCERT Exemplar Solutions Class 12th Chapter Twelve

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Correct option: B

CH₃−CH₂−C≡CH + H₂O CH₃−CH₂−CO−CH₃

Butan-2-one is produced when butyne is hydrated in the presence of Hg ions as a catalyst. The ketone is the product. After the triple bond is broken, the OH group attaches to the secondary carbocation.

This is a Short Answer Type Questions as classified in NCERT Exemplar

Yes, both reactions look to be the same, but they are not. To convert benzene to benzaldehyde, the Gatterman-Koch reaction is performed. Benzene is treated with an acid chloride in the presence of anhydrous AlCl₃ in acylation processes. The Gatterman-Koch reaction is used to make HCOCl in situ by reacting CO with HCl gas in the presence of anhydrous AlCl₃.

This is a Short Answer Type Questions as classified in NCERT Exemplar

Due to the development of polysubstitution products, ethylbenzene is usually made through acetylation of benzene followed by reduction and direct alkylation.

Due to resonance, the benzene ring must be deactivated. The electrophilic attacking agent is rarely produced by the benzene ring.

This is a Short Answer Type Questions as classified in NCERT Exemplar

Although all of them have a hydrogen atom connected to an oxygen atom (—O—H), carboxylic acids are more acidic than alcohols or phenols. This can be explained by the conjugate base's stability after  H+ ions have been removed from the acid and phenol.

This resonance hybrid may be presented as:-

This is a Short Answer Type Questions as classified in NCERT Exemplar

The presence of a lone pair of electrons on an atom of the OH group diminishes the electrophilic character of C through resonance; carboxylic acids contain a carbonyl group. As a result, the carbonyl atom's partial positive charge is lowered.

This is a Short Answer Type Questions as classified in NCERT Exemplar

Solution: Carbonyl group is polar in nature. Due to larger electronegativity of oxygen as compared to carbon, carbon acquires partial positive charge while O acquires partial negative charge.

Because of slight positive charge on C atom, it is attacked by nucleophiles and, therefore, undergoes nucleophilic addition reaction.
Ethylenic double bond is a non-polar bond and is a source of electrons. Therefore, it is attacked by electrophiles and undergoes electrophilic addition reactions.

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NO₂CH₂COOH  >  FCH₂COOH  > C₆H₅COOH

To begin, determine whether it has an acidic strength associated with it, and whether it is an electron donating or electron withdrawing group. Acidic strength increases as the number of electron withdrawing groups increases. The acidic strength reduces as the electron donating group increases. In decreasing order, the most influential acidic strength is −NO₂> −F> −C₆H₅.

This is a Short Answer Type Questions as classified in NCERT Exemplar

When alkaline KMnO₄ oxidises compound "B" with compound "A," acid is formed.

When compound "A" is reduced with LiAlH₄, it transforms into compound "B." The letter "B" stands for a type of alcoholic beverage.

When compounds "A" and "B" are heated with conc. H2SO4, compound "C" is formed, which has a fruity odour.