Find the Most Acidic Proton
Click on the most acidic atom
Common Questions
How do you find the most acidic proton in a molecule?
Look for the proton whose removal produces the most stable conjugate base. Consider resonance stabilization, electronegativity of the atom losing the proton, inductive effects, and orbital hybridization (sp > sp2 > sp3).
What makes a proton acidic?
A proton is more acidic when its conjugate base is more stable. Factors include: the atom it is attached to (O-H more acidic than C-H), resonance delocalization of the negative charge, nearby electron-withdrawing groups, and hybridization.
Why are carboxylic acid protons more acidic than alcohol protons?
Removing the O-H proton from a carboxylic acid produces a carboxylate anion where the negative charge is delocalized across two oxygen atoms by resonance. An alkoxide from an alcohol has the charge localized on one oxygen.
What is pKa and how does it relate to acidity?
pKa is the negative log of the acid dissociation constant. Lower pKa = stronger acid. Each unit decrease represents a 10-fold increase in acidity. Most organic functional groups have characteristic pKa ranges.