What is the priority order of factors like resonance, hybridization, solvation, etc. in determining the relative acidity or basicity of compounds in a list?
WARNING! Long answer! Here are my thoughts.
Anything that decreases the
I would identify the factors in the order 1.
There are six common strong acids. In order of increasing acidity, they are:
Any strong acid is stronger than most organic acids.
Some factors to consider are:
I put resonance stabilization of the anion first in the list.
The more resonance contributors a conjugate base has, the stronger the acid will be.
That partly explains why sulfuric acid is stronger than nitric acid.
It also explains why acetic acid (
(a) Acidity of H-X increases from left to right on the Periodic Table.
The exception is
(b) Acidity increases from top to bottom of the Periodic Table.
As you go down a group, the bond length becomes longer and weaker, and the charge density on the ion decreases.
Electronegative atoms draw negative charge toward themselves.
This weakens the H-X bond and stabilizes the conjugate base.
The effect decreases with distance from the acidic
Alkyl groups are electron-donating groups.
They push electron density onto the
The more alkyl groups, the weaker the acid.
As we go from
Alkynes are remarkably acidic compared to alkanes.
Here's a summary of the discussion.