Which of the following halogens produces oxygen when passed through a hot and concentrated solution of $KOH$?

One gas bleaches the colour of flowers by reduction while the other by oxidation. The two gases respectively are:

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:

Which of the following substances has the highest reducing power?

Observe the following reaction. This reaction represents:
$4 HCl + O_2 \xrightarrow[723 \ K]{CuCl_2} 2 Cl_2 + 2 H_2 O$

Fluorine is a stronger oxidising agent than chlorine because :
$(a)$ $F-F$ bond has a low enthalpy of dissociation.
$(b)$ Fluoride ion $(F^{-})$ has high hydration enthalpy.
$(c)$ Electron gain enthalpy of fluorine is less negative than chlorine.
$(d)$ Fluorine has a very small size.
Choose the most appropriate answer from the options given :