An aqueous solution of a halogen salt of potassium reacts with the same halogen $X_2$ to give $KX_3$,a brown-coloured solution,in which the halogen exists as the $X_3^-$ ion,$X_2$ acts as a Lewis acid,and $X^-$ acts as a Lewis base. The halogen $X$ is:

Consider the following statements about the oxides of halogens:
$A$. At room temperature, $OF_2$ is thermally stable.
$B$. Order of stability of oxides of halogens is $I > Br > Cl$.
$C$. $I_2O_5$ is used in the estimation of $CO$.
$D$. $ClO_2$ is used as a bleaching agent.
The correct statements are:

State the properties and uses of dichlorine.

Assertion : $SnI_4$ is an orange solid.
Reason : The colour arises due to charge transfer.

Explain the electron gain enthalpy values of elements of the $17^{\text{th}}$ group. Give reasons and explain.

Which of the following halogens undergoes disproportionation in water?