arhenius vs. bronsted -lowry acid

[sweatybrain]

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quick question: what's the difference between arhenius and bronsted-lowry acid? EK study guide didn't really help. It says something along the line of "arhenius acid donates proton," and "bronsted-lowry produces proton."

 

[willthatsall]

Arrhenius: Acids donate H+ in aqueous solution, Bases donate OH- in aqueous solution.

Bronsted-Lowry: Acids donate H+, Bases accept H+

*All Arrhenius (most specific) are included in Bronsted-Lowry definition, they are both included in lewis (least specific) definitions

*Conjugate acid/base pairs refer to bronsted-lowry definitions

Edited: This is my 1000th post, hooray for me. 👍

 

[Medikit]

You probably don't need to know it for the mcat, and its one of those things that you learn but really doesn't matter. Thinking of things in terms of proton donors and receivers works best for the mcat.

 

[mdsquared]

an arrhenius acid is a substance that when dissolved increases the H+ ion concentration. a base is a substance that when dissolved increases the OH- ion concentration.

a bronsted-lowry acid is a species donating a proton in a proton-transfer reaction. a base is a species that accepts a proton in a proton-transfer reaction. using this definition you can also relate the conjugate acide-base pairs. for example, CN- is a conjugate base to a weak acid (HCN), and HCN is a conjugate acid to a weak base (CN-)

These are two different definitions, but they pretty much mean the same thing. However, you cant relate the conjugate acid-base pairs when using the arrhenius definition, and I'm not really sure but I think I heard that the MCAT does ask something about the conjugate acid-base pairs.