When fluoride is heated with conc. $H_2SO_4$ and $MnO_2$,the gas evolved is:

Choose the $CORRECT$ reason for fluorine being a stronger oxidising agent than chlorine.
$I$. Low enthalpy of dissociation of $F-F$ bond
$II$. High hydration enthalpy of $F^-$
$III$. Low atomisation enthalpy of $F_2$

Which of the following is useful in the preparation of chlorine?

Identify $A, B, C$ and $D$ in the reactions:
$(I)$ $x Cl_2 + y NaOH \longrightarrow A + B + H_2 O_{(l)}$ (Cold,dil.)
$(II)$ $x Cl_2 + y NaOH \longrightarrow C + D + H_2 O_{(l)}$ (Hot,conc.)

Arrange the following in the order of property indicated for each set:
$(i)$ $F_{2}, Cl_{2}, Br_{2}, I_{2}$ - increasing bond dissociation enthalpy.
$(ii)$ $HF, HCl, HBr, HI$ - increasing acid strength.
$(iii)$ $NH_{3}, PH_{3}, AsH_{3}, SbH_{3}, BiH_{3}$ - increasing base strength.

The incorrect statement is: