Equilibrium Constant

Now that we understand what an acid is, we need a method of quantifying which acids are stronger and which are weaker. pH doesn’t work for this, let me explain why:

pH vs. pKa

The Ka (dissociation constant) describes the tendency of a molecule to break apart. In the case of acids, that specifically means donating protons, which is exactly what we are interested in knowing!

The pH and pKa scales really are completely different. Pardon my French! pKas are obviously something I’m really passionate about. 

Calculating pKa

This is the easiest kind of question you could get. Calculating pKa’s just takes some very simple math. 

Example: Calculate the pKa of ammonium and determine if it is a stronger acid than acetic acid.