Question

What are the corresponding anhydrides of the following oxyacids?
$HCl{O_4},HCl{O_3},HCl{O_2}$ and $HOCl$.
This question has multiple correct options
A.$HCl{O_4}:C{l_2}{O_3}$
B.$HCl{O_3}:C{l_2}{O_6}$
C.$HCl{O_2}:Cl{O_2}$
D.$HOCl:C{l_2}{O_4}$

Answer 1

Anhydrides are the compounds that are formed by removing or eliminating the water molecule from the parent molecule. The parent molecule can be known as oxyacid and the compound obtained after dehydration can be known as an anhydride. Chloric acid and Chlorous acid are oxyacids.

Complete answer:
Chemical compounds formed by dehydration are called anhydrides. Anhydrous means without water or the compound formed by removal of a water molecule. Anhydrides are formed from the parent molecules by dehydration. These parent molecules are known as oxyacids.
In the given question, four oxyacids were given.
Some of them are mixed anhydrides. Mixed anhydrides are the compounds that are formed by the removal of water molecules from two oxyacids.
$HCl{O_3}$ is the oxyacid of $C{l_2}{O_6}$. The reaction of dehydration will be as follows:
$C{l_2}{O_6} + {H_2}O \to HCl{O_3} + HCl{O_4}$
Thus, $C{l_2}{O_6}$ is the anhydride of $HCl{O_3}$ and $HCl{O_4}$
Given that$C{l_2}{O_6}$ is the anhydride of $HCl{O_3}$
Option B is the correct one.
$HCl{O_2}$ is the oxyacid of $Cl{O_2}$. The reaction of dehydration will be as follows:
$Cl{O_2} + {H_2}O \to HCl{O_2} + HCl{O_3}$
Thus, $Cl{O_2}$ is the anhydride of both $HCl{O_2}$ and $HCl{O_3}$
Given that $Cl{O_2}$ is the anhydride of both $HCl{O_2}$
Option C is the correct one.

Both B and C options are correct.

Note:
Oxyacids are simply parent molecules of anhydrides. Mixed anhydrides can have two parent oxyacids. Thus, in the given options the correct pair of oxyacids and anhydride must be taken. In the given options mixed anhydrides were also given, but only one oxyacid is given as a pair.