1° and 3° amine.

(i) Hell-Volhard-Zelinsky reaction Carboxylic acids having a-hydrogen are halogenated at the a-position. On treatment .with chlorine or bromine in the presence of small amount of red phosphorus, it gives a-halo carboxylic acids. The reaction is known as Hell-Volhard-Zelinsky reaction.

(ii) Decarboxylation reaction
Decarboxylation is a chemical reaction that takes place in carboxylic acid via the release of carbon dioxide (CO₂). It is an example of the cleavage of a carbon-carbon single bond.
(a) Using sodalime

(c) Decarboxylation of silver salts of carboxylic acids in presence of bromine (Hunsdiecker reaction).

(a) Ethanal to propanone

(b) Toluene to benzoic acid

(i) Wolff-Kishner Reduction
Carbonyl group are easily reduce by hydrazine followed by heating with strong base like alkali to


(ii) Etard Reaction
Toluene reacts with chromyl chloride in presence of CS₂ followed by hydrolysis produces benzaldehyde.

(i) Clemmensen reduction It involves reduction of carbonyl group of an aldehyde or ketone to methylene group to form a hydrocarbon. Clemmensen reduction is carried out in presence of Zn amalgam and conc. HCl.

It is widely used for the reduction of aldehydes and ketones which are sensitive to alkalies.
(ii) Cannizzaro reaction Aldehydes which do not have ∝-H atoms undergo Cannizzaro reaction on treatment with cone. alkali. In this reaction, one molecule of aldehyde is reduced to alcohol while another molecule is oxidised to salt of carboxylic acid.

Iodoform test Ethanal, because of the presence of CH₃CO-skeleton gives iodoform test whereas propanal due to the absence of such a skeleton does not.

(i) 


(ii) 

a. Tertiary butyl ketone does not give precipitate with sodium bisulphate whereas acetone does.
b. Dialkyl cadmium is considered superior to grignard reagent for the preparation of a ketone from an acid chloride.

(i) Gabriel's phthalimide synthesis: Phthalimide when treated with alcoholic potassium hydroxide is easily converted into potassium phthalimide which on treatment with alkyl halide followed by hydrolysis with acid or alkali yields phthalic acid and a primary amine.
(ii) Coupling reaction: It involves the reaction of benzene diazonium salts with phenols or aryl amines. Coupling of phenol takes place in mild alkaline solution while with aromatic 10 amines in mild, acidic medium.

The general reaction involved in Williamson's ether synthesis is given as

 

i) Iodoform test: Ethanal gives this test due to the presence of CH₃CO :
CH₃HO + 4NaOH + 3I₂ \(\longrightarrow \) CHI₃ + HCOONa + 3Nal + 3H₂0
Ethanal                                  (yellow ppt)
                                               loadform
CH₃CH₂CHO + 4NaOH + 3I₂ \(\longrightarrow \) No reaction
(ii) Sodium bicarbonate test: Benzoic acid gives brisk effervescence of CO₂ when react with NaHCO₃ while phenol does not give it, as it is a weak acid.

3-pentanol immediately gives turbidity with Lucas reagent but 2-pentanol gives turbidity in around five minutes.

(ii) Substitution always competes with elimination. Since 3° alkyl halides preferentially undergo elimination while 1°alkyl halides preferentially undergoes substitution, therefore, reaction
(i) will undergo elimination to give isobutylene while reaction
(ii) will undergo substitution to give t-butyl methyl ether.

(i) Add Tollen's reagent. Propanal will give silver mirror whereas propanone will not react.
(ii) Add NaHCO₃ solution. Benzaldehyde will not react whereas benzoic acid will give brisk effervescence due to CO₂.

1-Propanol will not react with I₂/NaOH to give iodoform.