Question

$Cl_2O_7$ is the anhydride of

• A. $HOCl$
• B. $HClO_2$
• C. $HClO_3$
• D. $HClO_4$

Answer 1

Answer: (D)

$HClO_4$

Answer 2

$Cl_2O_7$ is the anhydride of $HClO_4$. It reacts with water slowly to give perchloric acid
$Cl_2O_7 + H_2 O \to \underset{\text{Perchlororic acid}}{2HClO_4}$
Its structure is as follows

It is less reactive than other oxides of chlorine and does not react with $P, S$, coal or paper at room temperature.