Actors In Every Acid Base Reaction

by Kiley Lynch

Every acid base reaction has 4 actors. 

Before (or above) the arrow

  • The acid: this is the molecule giving up H+
  • The base: this is the molecule that receives H+

After the arrow

  • The conjugate base is the species formed after the acid has donated its H+
  • The conjugate acid is the species formed after the base has gained the H+

So the acid donates a proton, becoming the conjugate base, and the base accepts a proton, becoming the conjugate acid.

If you look at the patterns of bonds formed and bonds broken, it’s straightforward: we’re breaking the H-A bond and forming the H–B bond.

How can you tell if an acid-base reaction is favored or not? Here’s one clue: theconjugate acid should be a weaker acid than the starting acid, and the conjugate base should be a weaker base than the starting base.

How do we know if an acid-base reaction is favored or not? We have a tool for determining that! More tomorrow.

Thanks for reading! James

PS. Relevant post: Introduction to acid base reactions

P.P.S. Another relevant post – Walkthrough of acid-base reactions (series)