If the magnitude of Ka is small then very little of the left-side acid, HA, will have ionized. They are completely ionized in solution. There is no KOH in solution, only its ions are present. A very different approach is taken for WEAK bases, which do not contain the hydroxide ion. Small values of Kb mean very little of the WEAK base is ionized.
Similar complexities are possible for the other substances in the equilibrium expression.
M LiOH c. 2.0 M NaOH 4. Concentrations of hydrogen and hydroxide ions vary over a very wide range of magnitudes. A much more convenient way of dealing with this wide range of numbers uses a log scale of concentrations, i.e., the pH scale. Determine the pH and pOH for each of the solutions in problems 1 - 4 above.