AIIMS Chemistry Aldehydes Ketones Carboxylic Acids Class 12 Questions

Assertion : Glyceraldehyde reacts with 2 2 Br /H Oto form achiral compound Reason: –CHO and $\text{–CH}_{2}\text{OH}$ both are oxidized

$\text{H}-\overset{\substack{\text{O} \\ ||}}{\text{C}}-\text{H} + \text{CH}_3-\text{CH}=\text{O} \xrightarrow{\text{Conc. NaOH}}$ Find out the products of reaction

(1) $\text{C}_6\text{H}_5-\overset{\substack{\text{O} \\ ||}}{\text{C}}-\text{C}_6\text{H}_5$ (2) $\text{C}_6\text{H}_5-\text{CHO}$ (3) $\text{p}-\text{CH}_3-\text{C}_6\text{H}_4-\text{CHO}$ (4) $\text{p}-\text{CH}_3\text{O}-\text{C}_6\text{H}_4-\text{CHO}$

Above compounds can be differentiated by following reagent:

Final product of given Reaction :

Final product of given reaction:

Each of these questions contains two statements. Assertion (A) and Reason (R). Each of these questions also has four alternative choices, only one of which is the correct answer. You have to select one of the codes (a), (b), (c) and (d) given below. Assertion (A) Benzaldehyde is less reactive in comparison to ethanol towards nucleophilic attack. Reason (R) All the carbon atoms of benzaldehyde are sp²-hybridised.

Assertion (A): Benzaldehyde is more reactive than ethanal towards nucleophilic attack. Reason (R): The overall effect of $-I$ and $+R$ effect of phenyl group decreases the electron density on the carbon atom of the carbonyl group in benzaldehyde.

Benzaldehyde can be prepared from

Assertion (A) Benzaldehyde is less reactive in comparison to ethanol towards nucleophilic attack. Reason (R) All the carbon atoms of benzaldehyde are sp²-hybridised.

Assertion (A) Benzaldehyde is less reactive in comparison to ethanol towards nucleophilic attack. Reason (R) All the carbon atoms of benzaldehyde are sp²-hybridised.

Which of the following is the industrial method of preparation of acetaldehyde?

C₃H₆O did not give a silver mirror with Tollen’s reagent, but gave an oxime with hydroxylamine. It can give positive

Which of the following carboxylic acids undergoes decarboxylation easily?

CH2 = CH2 + H2O Pd2+ → CH3CHO

Which of the following carboxylic acids undergoes decarboxylation easily?

Assertion Aldol condensation is usually carried out in dilute solution of a strong base. Reason Concentrated solution of strong base involved Cannizzaro reaction.

Arrange the following compounds in increasing order of reactivity towards nucleophilic addition reaction. (I) $\text{C}_6\text{H}_5\text{COCH}_3$ (II) $\text{CH}_3\text{CO}-\text{C}_2\text{H}_5$ (III) $\text{C}_6\text{H}_5\text{CHO}$ (IV) $\text{Cl}-\text{CH}_2-\text{CHO}$

Salicylic acid can be easily prepared by reaction between

In a set of reactions, acetic acid yielded a product S. The structure of S would be:

Find the number of stereoisomers of 1,²⁻dihydroxy cyclopentane.

Cyclohexene on ozonolysis followed by reaction with zinc dust and water gives compound E. Compound E on further treatment with aqueous KOH yields compound F. Compound F is

Ethyl ester CH₃MgBr excess P. The product P will be

Compound A (molecular formula C₃H₆O) is treated with acidified potassium dichromate to form a product B (molecular formula C₃H₆O). B forms a shining silver mirror on warming with ammoniacal silver nitrate. B when treated with an aqueous solution of H₂NCONHNH₂, HCl and sodium acetate gives a product C. Identify the structure of C.

Assertion: Aldol condensation can be catalysed both by acids and bases. Reason: β-Hydroxy aldehydes or ketones readily undergo acid catalysed dehydration.

Assertion: Esters which contain α-hydrogens undergo Claisen condensation. Reason: LiAlH₄ reduction of esters gives acids.

Toluene on treatment with CrO₃ and (CH₃CO)₂O followed by hydrolysis with dil. HCl gives

Assertion : (CH₃)₃CCOC(CH₃)₃ and acetone can be distinguished by the reaction with NaHSO₃. Reason : HSO₃⁻ is the nucleophile in bisulphite addition.

Benzoic acid is treated with lithium aluminium hydride. The compound obtained is

CH₃CO₂C₂H₅ on reaction with sodium ethoxide in ethanol gives A, which on heating in the presence of acid gives B. Compound B is

C₆H₅CONHCH₃ can be converted into C₆H₅CH₂NHCH₃ by

Assertion : Alkyl isocyanides in acidified water give alkyl formamides. Reason : In isocyanides, carbon first acts as a nucleophile and then as an electrophile.

At higher temperature, iodoform reaction is given by

Assertion : Hydroxyketones are not directly used in Grignard reaction. Reason : Grignard reagents react with hydroxyl group.

The intermediate formed in aldol condensation is

The compound most suitable for the preparation of cyanohydrin is

Action of acetylene on dilute H₂SO₄ gives

CH₃COCH₃ can be converted to CH₃CH₂CH₃ by the action of

Strongest acid among the following is

CO₂ is liberated on adding sodium carbonate to a carboxylic acid. The carbon of CO₂ comes from

Salicylic acid is prepared from phenol by