Question

Which of the following reactions produce(s) propane as a major product?

• A.
• B.
• C.
• D.

Answer 1

Answer: (C), (D)

(a). This reaction is Kolbe's electrolysis. In this method an aqueous solution of $Na/K$ salt of a carboxylic acid on electrolysis gives alkane containing even number of $C$ atoms at the anode.

(b) Dehalogenation of Vicinal Dihalides
Vicinal dihalides are reduced in presence of $Zn/Zndust$ to form alkenes.

(c) In this reaction alkyl halide get reduced to alkane by $Zn,dil.HCl$. It inolves the cleavage of $C-X$.

(d) Soda Lime reaction: Here, carboxylic acid will undergo decarboxylation to form alkane containing one C atom less than the carboxylic acid.

Thus, reaction (c) and (d) leads to formation of propane.