Stop Memorizing Acid Base Definitions. Look for This Instead.

Added: 2026-05-06

[00:00:00]You learned three definitions for acids and bases, but how do you apply them to questions? An Arrhenius acid is one that gives you an H+ in water. An Arrhenius base gives you an OH-. A Brønsted-Lowry acid gives you an H+ in any solution. A base is one that accepts an H+. A Lewis acid accepts a pair of electrons. A base donates. For example, H2SO4 is an Arrhenius acid, NaOH an Arrhenius base.

[00:00:26]H2SO4 is also a Brønsted-Lowry acid in another solution. NH3 would be the base.

[00:00:32]A Lewis acid could be a carbonyl with a partially positive carbon, and a Lewis base could be an alkene with its pi electrons. But if you're asked a simple question about acids and bases, you don't have time for the definitions.

[00:00:46]Instead, look at the pattern. The acids are all positive or partially positive.

[00:00:50]The bases are negative or partially negative. We have lone electrons here and electrons here. And so, what you really need to know is that an acid is positive or partially positive, and a base is negative or partially negative in context of what you're comparing it to. See the full video below.