Question

Which of the following species represent mixed anhydride?
A.${N_2}{O_5}$
B.$C{l_2}{O_6}$
C.${N_2}{O_4}$
D.Both (2) and (3)

Answer 1

The anhydride is a chemical compound which is derived from the acid by eliminating water molecules. When the compound is reacted with water, if there is a formation of two acidic anhydride, then that type of anhydride is known as mixed anhydride. In the case of an acidic anhydride, which indicates the acidic oxide. And the functional group of acid anhydride is $R - COO - CO - {R^{'}}$.

Complete answer:
When dinitrogen pentoxide is reacted with water, there is a formation of only one acidic anhydride. Let’s see the reaction,
${N_2}{O_5} + {H_2}O \to HN{O_3}$
Hence, option (A) is incorrect.
When chloryl perchlorate is reacting with water, there is a formation of two acid anhydride and that is, $HCl{O_3}$ and $HCl{O_4}$. Chloryl perchlorate is a mixed anhydride of chloric acid and perchloric acid. Let’s see the reaction,
$C{l_2}{O_6} + {H_2}O \to HCl{O_3} + HCl{O_4}$
Hence, option (B) is correct.
If dinitrogen tetroxide reacts with water, there is a formation of two acidic anhydride. Which is, nitric acid and nitrous acid. Therefore, ${N_2}{O_4}$ is a mixture of nitric acid and nitrous acid. And the reaction is,
${N_2}{O_4} + {H_2}O \to HN{O_3} + HN{O_2}$
Hence, option (C) is correct.
Both two and three are examples of mixed anhydride.

Hence, the option (D) is correct.

Note:
Mixed anhydride is also known as double acid anhydride. Because, the compound gives the mixture of acid anhydride when it is reacting with water. Dinitrogen tetroxide, chloryl perchlorate etc is the example of mixed anhydride. and in acid anhydride, two acyl groups are attached by an oxygen atom and the acid anhydride in organic to initiate the acyl group.