The covalency and oxidation state respectively of boron in $$\left[\mathrm{BF}_{4}\right]^{-}$$, are :

Given below are two statements :

Statement I : Tropolone is an aromatic compound and has $$8 \pi$$ electrons.

Statement II : $$\pi$$ electrons of $$ > \mathrm{C}=\mathrm{O}$$ group in tropolone is involved in aromaticity.

In the light of the above statements, choose the correct answer from the options given below:

Identify the correct order of standard enthalpy of formation of sodium halides :

Match List I with List II

1 - Bromopropane is reacted with reagents in List I to give product in List II

Choose the correct answer from the options given below: