Bronsted vs. Lewis

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005199302
Posts: 108
Joined: Fri Sep 28, 2018 12:15 am

Bronsted vs. Lewis

Postby 005199302 » Sun Dec 02, 2018 2:18 pm

Are bronsted and Lewis acids the same? When is using one more correct than using the other?

Cody Do 2F
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

Re: Bronsted vs. Lewis

Postby Cody Do 2F » Sun Dec 02, 2018 2:24 pm

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.

Jordan Y4D
Posts: 25
Joined: Fri Sep 28, 2018 12:27 am

Re: Bronsted vs. Lewis

Postby Jordan Y4D » Sun Dec 02, 2018 4:41 pm

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.

Diana Bibireata 1B
Posts: 60
Joined: Fri Sep 28, 2018 12:23 am

Re: Bronsted vs. Lewis

Postby Diana Bibireata 1B » Sun Dec 02, 2018 4:57 pm

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.


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