Write the reagents required in the following reactions:

(i) CH₂ = CH − CH₂OH ¾ CH₂ = CH − CHO

(ii) CH₃− COOH ¾ CH₃− CONH₂

OR

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

(i) CH₃COCH₃, C₆H₅COCH₃, CH₃CHO (reactivity towards nucleophilic addition reaction)

(ii) Cl − CH₂− COOH, F − CH₂− COOH, CH₃ − COOH (acidic character)

(i) CH₂ = CH − CH₂OH CH₂ = CH − CHO

Primary alcohol vapours when passed over heated Cu at 573K, dehydrogenation takes place to give aldehyde.

(ii) CH₃− COOH + NH₃ ¾ CH₃COONH₄ CH₃− CONH₂

Carboxylic acid reacts with ammonia to give ammonium salt which on further heating gives amide.

OR

(i) Aldehydes are more reactive towards nucleophilic addition reaction than ketones due to steric and electronic reasons. Sterically, presence of 2 relatively large groups on ketone hinders the approach of nucleophile to carbonyl carbon as compared to that of only one group on carbonyl carbon. Electronically, in ketones 2 alkyl groups which are electron releasing decreases the electrophilicity of carbon.

But aromatic ketones are more reactive than aliphatic ketones because phenyl group is less electron releasing than alkyl group. Thus, it does not decrease the electrophilicity of carbonyl carbon as compared to that of alkyl carbon.

Therefore, the order of reactivity towards nucleophilic substitution reaction is CH₃COCH₃ < C₆H₅COCH₃ < CH₃CHO.

(ii) The presence of EWG i.e. Cl and F increases the acidity of carboxylic acids by stabilizing the negative charge of conjugate base by –I effect. And –I effect of F is greater than that of Cl.

Whereas presence of EDG i.e. –CH₃ decreases the acidity by destabilizing the negative charge of conjugate base by +I effect.

Therefore, order of acidic character:

F − CH₂− COOH> Cl − CH₂− COOH> CH₃ − COOH