Bronsted vs. Lewis
Moderators: Chem_Mod, Chem_Admin
Bronsted vs. Lewis
Are bronsted and Lewis acids the same? When is using one more correct than using the other?
-
- Posts: 62
- Joined: Fri Sep 28, 2018 12:23 am
Re: Bronsted vs. Lewis
A Bronsted acid is a proton donor and a Bronsted base is a proton acceptor. Conversely, a Lewis acid is an electron pair acceptor while a Lewis base is an electron pair donor. They both describe the same thing, the only difference is what is being focused on (the proton or the electron pair). For example, H20 + HCl -> H30+ + Cl-. H20 is both the Bronsted base (because it's accepting a proton AKA the H+ atom) and the Lewis base (because it's donating an electron to Cl to make it Cl-). HCl is both the Bronsted acid (it donated its H+) and the Lewis acid (it accepted the electron from H20.
-
- Posts: 25
- Joined: Fri Sep 28, 2018 12:27 am
Re: Bronsted vs. Lewis
They are the same thing, simply using two different reactions that occur in the acid-base dichotomy. A lewis base is any species that donates an electron pair, whereas a bronsted base is any species that accepts protons. These things occur at the same time, but the bronsted definition discusses the movement of protons (H^+ ions) whereas the lewis definition discusses the sharing of electron pairs.
-
- Posts: 60
- Joined: Fri Sep 28, 2018 12:23 am
Re: Bronsted vs. Lewis
A bronsted acid is a proton donor and a bronsted base is a proton acceptor. A lewis acid accepts an electron pair and a lewis base donates the electron pair. Both essentially mean the same thing however the lewis definition is a little more general.
In the example: NH3 + H2O → NH4+ + OH- a hydrogen from the water bonds to the NH3. The NH3 accepts the proton (H+) and provides both electrons in one of the N-H bonds. Therefore the NH3 is a bronsted base and a lewis base.
In the example: NH3 + H2O → NH4+ + OH- a hydrogen from the water bonds to the NH3. The NH3 accepts the proton (H+) and provides both electrons in one of the N-H bonds. Therefore the NH3 is a bronsted base and a lewis base.
Return to “Bronsted Acids & Bases”
Who is online
Users browsing this forum: No registered users and 6 guests