Question

Action of $PC{l_5}$ on $S{O_2}$ chiefly yields:
(A) $POC{l_3}$
(B) ${P_4}{S_3}$
(C) $S{O_2}C{l_2}$
(D) $S{O_3}$

Answer 1

First of all we should know the chemical name of $PC{l_5}$ is Phosphorus pentachloride. It is one of the most important phosphorus chlorides. It finds use as a chlorinating reagent.Now we should know the chemical name of $S{O_2}$ that is Sulphur dioxide. It is a toxic gas, which is mainly responsible for the smell of burnt matches. It is released naturally by volcanic activity and is also produced by the burning of fuel.

Complete step-by-step answer:
First we should aware of the process through which the action of $PC{l_5}$ on $S{O_2}$ that is
$PC{l_5}\, + S{O_2} \to \,POC{l_3}\, + \,SOC{l_2}$
In this reaction there are two products which are$POC{l_3}\, and \,SOC{l_2}$.
Hence in this reaction one is the main product and the other is the byproduct.
The main product in this reaction is $POC{l_3}$ and the byproduct is the $SOC{l_2}$.
So the correct option is A. which is $POC{l_3}$
Properties of $POC{l_3}$
1.It is a type of industrial raw material.
2.It is a colorless and transparent liquid.
3.It has an unpleasant irritating odor.
4.It will smoke intensely in humid air.
5.It’s molecular geometry is tetrahedral with asymmetric charge distribution around the central atom. Therefore this molecule is polar in nature.

Hence (A) is correct option.

Note: The melting point of $POC{l_3}$ is ${1.25^0}C$ while boiling point of $POC{l_3}$ is ${105.1^0}C$. $POC{l_3}$ is mainly used as a dehydrating agent in chemical laboratories. It is used as a dehydrating agent in the preparation of nitriles from primary amides. It is also used as a dehydrating agent in the Bischler- Napieralski reaction.