BF₃ and the Incomplete Octet: A Bonding Exception

The video tutorial explains how boron trifluoride can satisfy its octet by utilizing a lone electron pair from fluorine. This results in the formation of three resonating structures, which are unstable due to the formal charges on boron and fluorine. The shorter bond length supports these structures. Additionally, the reaction of boron trifluoride with ammonia is better explained using the Levy structure, where boron has six valence electrons, leading to four resonating structures.

How does boron trifluoride achieve an octet?

• By losing electrons to nitrogen

• By gaining electrons from oxygen

• By transferring a lone electron pair from fluorine

• By sharing electrons with hydrogen

What is the result of the electron pair donation from fluorine to boron?

• Creation of three resonating structures

• Formation of a single bond

• Stabilization of the molecule

• Increase in molecular weight

Why are the resonating structures of boron trifluoride considered unstable?

• Because both boron and fluorine have neutral charges

• Because boron has a negative formal charge and fluorine has a positive formal charge

• Because fluorine has a negative formal charge

• Because boron has a positive formal charge

What supports the existence of the resonating structures in boron trifluoride?

• The longer bond length

• The shorter bond length

• The presence of hydrogen bonds

• The absence of formal charges

How is the reaction of boron trifluoride with ammonia better explained?

• By using Lewis structures

• By using molecular orbital theory

• By using VSEPR theory

• By using Levy structures