Question:
BF3 does not have proton but still acts as an acid and reacts with NH3. Why is it so? What type of bond is formed between the two?
Solution:
According to Lewis concept e- deficient species are called lewis acid so BF3 will act as a lewis acid while NH3 (N=1s2 2s2 2p3) has a lone pair so it will act as a lewis base and it will donate its lone pair to the empty p-orbital of Boron through a coordinate bond to form an adduct.