The gas produced on heating $MnO_2$ with conc. $HCl$ is

Which of the following are not in accordance with the property mentioned against them?
$I$. $F_2 > Cl_2 > Br_2 > I_2$ : Oxidising power
$II$. $MI > MBr > MCl > MF$ : Ionic character of metal halide
$III$. $F_2 > Cl_2 > Br_2 > I_2$ : Bond dissociation enthalpy
$IV$. $HI < HBr < HCl < HF$ : Hydrogen-halogen bond strength

Chlorine reacts with hot and concentrated $NaOH$ and produces compounds $(X)$ and $(Y)$. Compound $(X)$ gives a white precipitate with silver nitrate solution. The average bond order between $Cl$ and $O$ atoms in $(Y)$ is

Number of $Cl=O$ bonds in chlorous acid,chloric acid and perchloric acid respectively are :

When $SbF_5$ reacts with $XeF_4$ to form an adduct,the shapes of cation and anion in the adduct respectively are

The correct order of acidity of $HClO$, $HBrO$, and $HIO$ is