Lewis Acids and Bases

[Kaethe Zappacosta 2L]

#6 on the online homework asks you if compounds are acids or bases, and I am confused on how to tell.
It asks about SO2, H2O, and B(OH)3
Because using B(OH)3 as an example, isn't the B3+ the lewis acid, and the OH- the lewis base? What is it overall?

[Simone Byun 1F]

Drawing out the lewis structures was helpful in figuring out if it was an acid or base. Anions will be bases as they can give away electrons, but also if a molecule has extra lone pair electrons it will also be a base. Alternatively, cations will be acids as well as molecules where the central atom does not fill or uses doubles bonds to fill the octet. Using B(OH)3, B will only have 6 atoms, so it can accept electrons, thus it is an acid.

[bree_wray_14a]

#6 on the online homework asks you if compounds are acids or bases, and I am confused on how to tell.
It asks about SO2, H2O, and B(OH)3
Because using B(OH)3 as an example, isn't the B3+ the lewis acid, and the OH- the lewis base? What is it overall?

Hi, I would first suggest to draw out the lewis structures for those molecules and then you know than anions will be bases and cations will be acids. Hope this helps!

[Vincent Nguyen 3G]

I think an important distinction is between Bronsted Acids/Bases and Lewis Acids/Bases. I think most people are more familiar with Bronsted Acids/Bases where Bronsted Acids donate protons and Bronsted Bases accept protons. Lewis Acids/Bases focus on Lewis Acids accepting electron pairs and Lewis Bases donating electron pairs. Given, a Bronsted Acid is also a Lewis Acid, the only difference is what we are focused on transferring.