In which pair or pairs is the stronger bond found in the first species?

I. O$$_2^{2 - }$$, O₂; II. N₂, N$$_2^{+ }$$; III. NO⁺, NO^$$-$$

In the molecules CH₄, NF₃, NH$$_4^ + $$ and H₂O

The most volatile compound among the given option is

The structure of CIF₃ is