[ AlF 6]3- exists, while [ BF 6]3- does not. Choose the most appropriate reason.

Question

[ AlF 6]3- exists, while [ BF 6]3- does not. Choose the most appropriate reason. (A) Boron is smaller in size (B) Boron cannot expand it valence shell (C) Aluminium shows variable valency (D) Aluminium is more electropositive

Tardigrade Admin · Accepted Answer

The most appropriate reason is that, boron cannot expand its valence shell and its maximum valency is limited to 4 , while Al can expand its valence shell and hence can form [ AlF 6]3-.

Q. $[A l F_{6}]^{3 -}$ exists, while $[B F_{6}]^{3 -}$ does not. Choose the most appropriate reason.

Boron is smaller in size

Boron cannot expand it valence shell

Aluminium shows variable valency

Aluminium is more electropositive

The most appropriate reason is that, boron cannot expand its valence shell and its maximum valency is limited to $4$ , while $A l$ can expand its valence shell and hence can form $[A l F_{6}]^{3 -}$ .

Q. [AlF6​]3− exists, while [BF6​]3− does not. Choose the most appropriate reason.