How does Bronsted-Lowry define acids and bases?
A Brønsted-Lowry acid is any substance (molecule or ion) that can donate a hydrogen ion (
A Brønsted-Lowry base is any species that can accept a hydrogen ion (
Basically, acids are proton donors and bases are proton acceptors.
Take the reaction below for example:
Hydroiodic acid (
The Brønsted-Lowry theory also introduces the concept of conjugate acid-base pairs. A conjugate acid-base pair are two species that differ by a (
Based on the reaction above, the ammonium ion
Here's a tip to let you know which substance is the conjugate acid and which substance is the conjugate base:
A conjugate base has one less (
#H^(+)#) proton than the acid you started with.
A conjugate acid has one more (
#H^(+)#) proton than the base you started with.
Here's a general depiction of conjugate acid-base pairs: