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## Main Question or Discussion Point

I am a little confused about the meaning of pH, especially when you have a basic solution. I know that [itex] pH = -log[H^{+}] [/itex], but I don't understand how you can have a pH for a basic solution. Don't basic solutions only produce hydroxide ions?

I know that [itex] pH + pOH = 14 [/itex] but why this equation be true for anything other than water?

For example, consider the basic solution of ammonia to produce ammonium ions and hydroxide ions.

[tex] NH_{3}(g) + H_{2}O(l) \rightleftharpoons NH^{+}_{4}(aq) + OH^{-}(aq) [/tex]

Knowing the concentrations and the base-dissociation constant, we could easily calculate [itex][OH^{-}][/itex] and from that we can get pOH, but what is the significance of pH if there is no [itex]H^{+}[/itex] ions?

I know that [itex] pH + pOH = 14 [/itex] but why this equation be true for anything other than water?

For example, consider the basic solution of ammonia to produce ammonium ions and hydroxide ions.

[tex] NH_{3}(g) + H_{2}O(l) \rightleftharpoons NH^{+}_{4}(aq) + OH^{-}(aq) [/tex]

Knowing the concentrations and the base-dissociation constant, we could easily calculate [itex][OH^{-}][/itex] and from that we can get pOH, but what is the significance of pH if there is no [itex]H^{+}[/itex] ions?