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Calculating pH and pOH. pH. pH: “potential of hydrogen” - A way of expressing the hydrogen ion concentration. pH = - log [H + ]. [H + ] = the hydrogen ion concentration. Calculating pH.
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pH pH: “potential of hydrogen” - A way of expressing the hydrogen ion concentration pH = - log [H+] [H+] = the hydrogen ion concentration
Calculating pH Calculate the pH values using the equation pH = - log [H+]. Do you notice a pattern? 3.0 5.0 7.0 9.0 12.0
How do we calculate [H+] if we know the pH? pH = - log [H+] [H+] = the hydrogen ion concentration [H+] = 10-pH
Calculating [H+] Calculate the [H+] values using the equation [H+] = 10-pH. Do you notice a pattern? 1 x 10-3 M 1 x 10-5 M 1 x 10-7 M 1 x 10-9 M 1 x 10-12 M
Calculating pH [H+] > 1 x 10-7 [H+] = 1 x 10-7 [H+] < 1 x 10-7
The pH Scale - As pH increases, [H+] decreases - As pH decreases, [H+] increases
pOH pOH: “potential of hydroxide” pOH = - log [OH-] Just like pH: - pOH is a convenient way of expressing the hydroxide ion concentration [OH-] = the hydroxide ion concentration Just like [H+]: [OH-] = 10-pOH pH + pOH = 14