Chemistry NCERT Exemplar Solutions Class 12th Chapter Twelve

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

Correct option: B

When a primary alcohol, such as Butan-1-ol, reacts with a powerful oxidising agent, such as KMnO₄, it produces carboxylic acid, however when a secondary alcohol, such as Butan-2-ol, is oxidised under the pressure of KMnO₄, it produces ketone. As a result, option B is right.

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

Correct option: C

_I2 and NaOH It is an iodoform reaction involving methyl ketones, the solution is the correct reagent. Because the reactants and product have double bonds, double bonds do not work throughout the reaction. There are also ketone and carboxylic groups present. The ketonic group is oxidised under the carboxylic group during the process. 

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

Correct option: B

The position of a functional group in the same carbon chain differs in positional isomerism. The functional group in the chemical or the unsaturated double or triple bond in the compound can help us figure it out.

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

Ans: Correct option: D

Tautomers are structural isomers that exist in two or more interconvertible structures of a single chemical molecule. Tautomerism transforms 'A' into acetone.

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

Correct option: B

In KOH adds to the compound

Due to the production of a stable conjugate base after hydronium is removed from phenol, it is more stable than alcohol.

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

Correct options: D

Aldehydes without a - hydrogen atom are the subject of Cannizaro's reaction.

Option D, CH₃CHO has 3 alpha  hydrogen atoms and it does not give Cannizaro's reaction 

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

Correct option: C

Acetones belong to the ketonic functional category. To distinguish between aldehyde and ketone, utilise Fehling's solution. Carbonyl groups are found in sodium hydrogen sulphite, phenyl hydrazine, and Grignard reagent. Ketones and aromatic aldehydes do not react with Fehling's solution.

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

Correct option: B

When phenol reacts with acid chloride in the presence of an alkali, the alkali is pyridine, and the acid chloride is benzoyl chloride, compound C₆H₅OCOC₆H₅ is formed. During this process, pyridine is utilised to neutralise 4HCl.

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

Correct option: C

Because the phenoxide ion produced is stabilised by resonance, phenol is more acidic than ethanol. When it comes to ethanol, resonance does not help to stabilise the phenoxide ion. The acidity of chloroacetic acid is higher than that of acetic acid. Alcohols and phenols are less acidic than carboxylic acids.

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

Correct option: B or (ii)

In nucleophilic addition processes, the reactivity of aldehydes and ketones are steric factors. The carbonyl group with the highest positive charge will be the most reactive, and if these groups have a positive inductive impact, the attack tendency will be reduced.