How is pOH determined?

1 Answer
anor277
Jun 4, 2016

pOH is detemined equivalently to pH, but pH+pOH=14 under standard conditions.

Explanation:

pH = -log_10[H_3O^+]

pOH = -log_10[HO^-]

Now K_w = [H_3O^+][HO^-] = 10^(-14)" at 298K".

Thus -log_10K_w=-log_10[H_3O^+] -log_10[HO^-]

=-log_10(10^-14) = +14

And thus pOH+pH=14 under standard conditions.

You should review the logarithmic function if you have any problem with this treatment. You should review it anyway, because I might have made a mistake.

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