Write the reagents required in the following reactions :

(i)

(ii)

OR

Arrange the following compounds inn 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) The reagents are – Pyridinium Chlorochromate (PCC) in isopropanol (C₅H₅NHCrO₃Cl) or Cu at 573K. When CH₂=CH—CH₂OH, a secondary alcohol is treated with PCC or at Cu at 573K, it undergoes oxidation and dehydrogenation to give an aldehyde CH₂=CH—CHO.

(ii) NH₄OH or liquid NH₃ or heat. Treating carboxylic acids with liquid ammonia at high temperatures gives amides after substitution reaction.

OR

(i)

Aldehydes and ketones undergo nucleophilic addition reactions unlike alkenes which undergo nucleophilic substitution. Aldehydes are generally more reactive than ketones both sterically and electronically, so CH₃CHO will be more reactive than CH₃COCH₃ and C₆H₅COCH₃. Nucleophiles are negatively charged entities and the positivity of carbon is due to the carbonyl group which facilitates nucleophilic addition. Thus positivity of carbon in carbonyl group is in order III > I > II. Due to +I effect of –CH₃ group and Benzene ring - cloud, of tertiary carbonyl carbon in (II) is decreased much more than (I) and (III). Thus nucleophilic addition happens in the order III > I > II.

(ii) In the case of carboxylic acids, their acidity can be deduced on reaction with metals and alkalies. Reaction with them leads to evolution of hydrogen. Substituents may affect the stability of the conjugate base of the carboxylic acid and thus, also the acidity. Electron withdrawing groups like halogen atoms increase the acidity of the carboxylic acid compared to its parent acid. The higher the electron withdrawing capacity of the atom, the higher acidity of the acid. The formation of ions of the given compounds on release of hydrogen is given as follows:

The acidity order is II > I > III.