Question

During ammonium reaction of BF3, only one ammonium molecule solvates BF3, why?

Answer 1

BF3 is a Lewis acid and NH3 is a Lewis base

BF3 has 1 empty orbital(electron poor) and NH3 has one lone pair hence one ammonium can solvate only one BF3

I hope this helps ( ╹▽╹ )