Illustrate the following name reactions giving suitable example in each case: (i) Clemmensen reduction (ii) Hell-Volhard-Zelinsky reaction. How are the following conversions carried out?

(a) (i) Clemmensen reduction
The carbonyl group of aldehydes and ketones is reduced to CH_2 group on treatment with zinc-amalgam and concentrated hydrochloric acid. This is known as Clemmensen reduction. (Ref. image 1)
(ii) Hell-volhard-zelinsky (HVZ) reaction
Carboxylic acids having an α- hydrogen are halogenated at the α-position on treatment with chlorine or bromine in the presence of a small amount of red phosphorus to give α-halocarboxylic acids. The reaction is known as Hell-Volhard-Zelinsky reaction.
R−CH₂−COOH (i) X₂/Red phosphorus ———→ (ii) H₂O R−CH−COOH
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X
X = Cl, Br α-Halocarboxylic acid
(b)- (i) (Ref. image 2)
(ii) CH₃CH₂CH₂CH₂CH₂OH (i) K₂Cr₂O₂/H₂SO₄ ———→ (ii) Dil. H₂SO₄ CH₃CH₂CH₂COOH
Butanol Butanoic acid
(iii) (Ref. image 3)