Question

Which reaction is correct in the conversion of chloroform to acetylene
A.\[{\rm{CHC}}{{\rm{l}}_{\rm{3}}} + {\rm{AgN}}{{\rm{O}}_{\rm{3}}}\]
B. \[{\rm{CHC}}{{\rm{l}}_{\rm{3}}} + {{\rm{O}}_2}\]
C. \[{\rm{CHC}}{{\rm{l}}_{\rm{3}}} + {\rm{HN}}{{\rm{O}}_{\rm{3}}}\]
D. \[{\rm{CHC}}{{\rm{l}}_{\rm{3}}} + {\rm{Ag}}\]

Answer 1

Hint: Chloroform is also known as trichloromethane. Its chemical formula is \[{\rm{CHC}}{{\rm{l}}_{\rm{3}}}\]. It is a colourless gas possessing a strong smell. It is used as a solvent in many chemical reactions.

Complete Step by Step Solution:
Let’s discuss the double displacement reaction in detail. In this reaction, the ions of the two reactants got exchanged with each other and the formation of new compound occurs. One example of double displacement reaction is,
\[{\rm{KBr}} + {\rm{AgN}}{{\rm{O}}_{\rm{3}}} \to {\rm{KN}}{{\rm{O}}_{\rm{3}}} + {\rm{AgBr}}\]

Here, we have to find out the option which is the correct method of conversion of chloroform to acetylene.
The reaction of chloroform with \[{\rm{AgN}}{{\rm{O}}_{\rm{3}}}\] gives silver chloride. So, it is not the correct conversion of chloroform to acetylene. Therefore, option A is incorrect.
 The reaction of chloroform with \[{{\rm{O}}_2}\] gives carbonyl chloride. So, it is not the correct conversion of chloroform to acetylene. Therefore, option B is incorrect.

The reaction of chloroform with \[{\rm{HN}}{{\rm{O}}_{\rm{3}}}\] gives tear gas and water. So, it is not the correct conversion of chloroform to acetylene. Therefore, option C is incorrect.

When the chloroform undergoes a reaction with silver, the double displacement reaction occurs and ions are exchanged and acetylene forms. The other product is Silver chloride. The reaction is,
\[{\rm{2CHC}}{{\rm{l}}_{\rm{3}}} + 6Ag \to {{\rm{C}}_{\rm{2}}}{{\rm{H}}_{\rm{2}}} + {\rm{6AgCl}}\]
So, products formed are acetylene (\[{{\rm{C}}_{\rm{2}}}{{\rm{H}}_{\rm{2}}}\]) And silver chloride (AgCl).
Hence, the option D is right.

Note: The iodoform test also helps to distinguish between methanol and ethanol. Ethanol whose chemical formula is \[{\rm{C}}{{\rm{H}}_{\rm{3}}} - {\rm{C}}{{\rm{H}}_{\rm{2}}} - {\rm{OH}}\] possesses alpha hydrogens. And it gives the positive iodoform test. But, due to the absence of alpha hydrogen atoms in methanol( whose chemical formula is HCHO), it gives a negative iodoform test.