6A.15 question from textbook

[205743684]

6A.15 Draw the Lewis structure or symbol of each reactant, identify the Lewis acid and the Lewis base, and then draw the Lewis structure of the product (a complex) for the following Lewis acid–base reactions:

PF5 + F- ------- ?

Cl- + SO2 ------- ?

I know lewis acids accept electrons and lewis bases give off electrons but don't know how we would identify the bases and acids considering the ions have a full outer shell. Also how would we get to the products formed?

[Sophia Olender 2J]

PF5 has no lone pairs while F- has 4 lone pairs (8 available valence electrons). Therefore, F- is the Lewis base (LP donor) and PF5 is the Lewis acid (LP acceptor). The product is a complex of the acid and base, meaning the two reactants combine to form one molecule. This results in PF6- (negative so charge is balanced on both sides).

Cl- has 4 lone pairs (8 available valence electrons), so it is a Lewis base (LP donor). SO2 also has a lone pair, but sulfur can have an expanded octet, so it can act as a Lewis acid and accept another lone pair of electrons.