Write two uses of $ClO_2$.

Justify by giving reactions that among halogens,$F_{2}$ is the best oxidant and among hydrohalic acids,$HI$ is the best reductant.

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{I}_2O_5 + H_2O \longrightarrow HIO_3$

Write the redox reaction between fluorine and water.

Which of the following statements is correct regarding halogens?

$A$ solid $A$ which has photographic effect reacts with the solution of a sodium salt $B$ to give a pale yellow precipitate $C$. The sodium salt $B$ on heating with concentrated $H_2SO_4$ gives brown vapours. Identify $A$,$B$,and $C$.