The correct decreasing order of boiling point of hydrogen halides is

The reaction of $HClO_3$ with $HCl$ gives a paramagnetic gas,which upon reaction with $O_3$ produces

Why are halogens strong oxidising agents?

The anhydride of the oxoacid $HOCl$ is

Assertion : The halogens absorb visible light.
Reason : All halogens are coloured.

The correct statement$(s)$ regarding $(i) HClO$,$(ii) HClO_2$,$(iii) HClO_3$,and $(iv) HClO_4$ is(are):
$(A)$ The number of $Cl=O$ bonds in $(ii)$ and $(iii)$ together is two.
$(B)$ The number of lone pairs of electrons on $Cl$ in $(ii)$ and $(iii)$ together is three.
$(C)$ The hybridization of $Cl$ in $(iv)$ is $sp^3$.
$(D)$ Amongst $(i)$ to $(iv)$,the strongest acid is $(i)$.