Question

In Clemmensen reduction carbonyl compound is treated with ________.
A.zinc amalgam + HCl
B.sodium amalgam + HCl
C.zinc amalgam + nitric acid
D.sodium amalgam + ${\text{HN}}{{\text{O}}_{\text{3}}}$

Answer 1

The Clemmensen reduction is an organic reaction used to reduce an aldehyde or ketone to an alkane using amalgamated zinc and hydrochloric acid.

Complete answer:
Clemmensen reduction reaction is one of the most powerful reduction methods in whole organic chemistry.
Clemmensen reaction is named after a Danish chemist, Erik Christian Clemmensen.
Clemmensen reduction conditions are effective and favour reducing aryl-alkyl ketones. With an aliphatic or cyclic ketone, Clemmensen reduction reaction uses activated zinc amalgam in a solution of hydrochloric acid, to make this solution more effective acetic anhydride or diethyl ether is used. The substrate used in this reaction should be able to tolerate the acidic conditions of Clemmensen reduction reaction.
Amalgams are mercury and other metal alloys. They are one of the oldest reducing agents. In the Clemmensen reduction reaction, hydrogen chloride, which is an acid, does the work of protonation of ketone, and the electrons from zinc amalgam are given to carbon atoms.

Therefore, the correct option is A.

Note:
For manufacturing of zinc amalgam:
High quality of zinc and mercury (ll) chloride should be used.
Zinc dust amalgam is made by dissolving 20g of mercury chloride with a solution of 10ml of concentrated hydrogen chloride acid in 300 ml of distilled water and them quickly stirring it.
Later, adding hundred-gram zinc dust of 95 percent purity. And then stirring it again.
For manufacturing of hydrogen chloride:
There are many ways of making hydrogen chloride acid.
Hydrogen chloride acid can be formed by dissolving hydrogen chloride in water here by forming hydrogen chloride acid
Many other processes by which hydrogen chloride acid is made in industries or labs.