Statement I : Fluorination of Ethane is explosive.

Statement II : Iodination of Ethane is reversible. 

Statement I : F₂ is highly reactive towards free radical reactions.

                       Propagation steps are highly exothermic and explosive.

Statement II : ${\mathrm{C}}_2{\mathrm{H}}_5-\mathrm{H}+{\mathrm{I}}_2\stackrel{ }{\to }{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{I}+\mathrm{HI}$ 

HI is a good reducing agent. 

It reduces ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{I}$ to ${\mathrm{C}}_2{\mathrm{H}}_6$.

Backward reaction occurs.

To prevent backward reaction, the reaction is carried out in presence of oxidizing agents.

Ex : ${\mathrm{HIO}}_3,{\mathrm{HIO}}_4,{\mathrm{HNO}}_3$ etc.

These oxidizing agents oxidize HI to I₂ and prevent backward reaction.

$5\mathrm{HI}+\mathrm{HI}{\mathrm{O}}_3\stackrel{ }{\to }3{\mathrm{I}}_2+3{\mathrm{H}}_2\mathrm{O}$