Ionic bases dissolving in $H_2O$ - ionic compounds dissociate into constituent ions. Not ionised.
e.g. $NaOH_{(s)}\stackrel{\mathrm{H_2O}}{\longrightarrow}Na^+_{(aq)}+OH^−_{(aq)}$
+
+## pH values
+
+Acid/base/neutral not equivalent to pH (logarithmic scale)
+
+In water at 25C: $[H_3O^+] \times [OH^-]=10^{-7} \therefore \text{pH}=7$
+
+$$\text{pH} = -\log[H_3O^+]=-\log[H^+]$$
+$$[H_3O^+]=10^{-\text{pH}}$$