large value for Ka means that the concentrations of ions are relatively high.
Therefore, the smaller the ionization constant of an acid, the weaker the acid.
Thus, of the three acids referred to above, the ionization constants show that the
weakest is boric acid, and the strongest, acetic acid. It should be remembered
that, in all cases where ionization constants are used, the electrolytes must be
weak in order to be involved in ionic equilibria.
TIP
Kw incorporates the [H 2 O]^2.Ionization Constant of Water
Because water is a very weak electrolyte, its ionization constant can be expressed
as follows:
From this expression, we see that for distilled water [H 3 O+] = [OH−] = 1 ×10 −7. Therefore, the pH, which is −log[H 3 O+], is
The pH range of 1 to 6 is acid, and the pH range of 8 to 14 is basic. See the chart
below.
TIP
Know the meaning of the pH scale.