Question

Ethanol is converted into ethyl chloride by reacting with
A. $C{l_2}$
B. $SOC{l_2}/Py$
C. $HCl$
D. $NaCl$

Answer 1

Hint:The conversion of ethanol to ethyl chloride is a nucleophilic substitution reaction, the reagent which can easily give nucleophilic -Cl group can be used as an reagent for this reaction.

Complete step-by-step answer:In order to convert ethanol into ethyl chloride we need to react ethanol with $SOC{l_2}$
The reaction that will take place is given as follows:
$C{H_3}C{H_2}OH + SOC{l_2} \to C{H_3}C{H_2}Cl + S{O_2} + HCl$

In the above reaction $SOC{l_2}/Py$ is used to replace $OH$ by $Cl$

When ethanol reacts with $SOC{l_2}$ we get ethyl chloride, sulphur dioxide and hydrochloric acid as the products.
This is a good method of preparation of alkyl halide. By-products of this reaction are gaseous in nature.
This reaction follows $S{_N}1$ mechanism.
Therefore, the correct answer is $SOC{l_2}/Py$ .

Option ‘B’ is correct

Additional Information: Ethanol is a fuel made from plant material. It’s an organic compound which is volatile, flammable, colourless liquid with a wine-like odour and pungent taste.
Thionyl chloride is an inorganic compound with chemical formula $SOC{l_2}$. It is a moderately volatile colourless liquid with an unpleasant odour. The given method is not applicable for the preparation of aryl halides because the C-O bond in phenols has a partial double bond character and is not easy to break double bond in comparison to single bond.

Note: It should be noted that, When making alkyl chlorides from alcohols, thionyl chloride is favoured. Thionyl chloride is favoured because its byproducts, $S{O_2}$ and $HCl$ , are gaseous and can easily escape to the atmosphere while still leaving alkyl chloride behind.