Correct Answer - 3
`Cl_(2)O_(6)`, a dark red liquid which freeze at `-180^(@)C` to give a yellow solid is always in equilibrium with the monomer `ClO_(3)`. It is usually made from `ClO_(2)` and `O_(3)`
`2ClO_(2)+2O_(3)rarr Cl_(2)O_(6)+2O_(2)`
The structure of neither the liquids nor the solids is known .Both are diamagnetic, and so have no unpaired electrons. Possible structures are :
It is strong oxidizing agent and explodes on contact with grease. Hydrolysis of `Cl_(2)O_(6)` with water or alkali gives chlorate and perchlorate:
`Cl_(2)O_(6)+2NaOH rarr underset("Chlorate")(NaClO_(4))+underset("Perchlorate")(NaClO_(4))+H_(2)O`
`Cl_(2)O_(6)+H_(2)O rarr HClO_(3) + HACIO_(4)`
reaction with anhdyederous `HF` is reversible :
`Cl_(2)O_(6)+HF hArr FClO_(2) +HClO_(4)`
It also reacts with nitrogen oxide:
`Cl_(2)O_(6)+N_(2)O_(4)rarrClO_(2)+[NO_(2)]^(+)[ClO_(4)]^(-)`