Barrons SAT Subject Test Chemistry, 13th Edition

(^) pH = −log [10−1]
3rd
step.
The logarithm of 10−1 is −1
so
pH = −(−1)
4th
step.
The pH then is = 1.
Because water has a normal H+ concentration of 10−7 mole/liter because of
the slight ionization of water molecules, the water pH is 7 when the water is
neither acid nor base. The normal pH range is from 0 to 14.
The pOH is the negative logarithm of the hydroxide ion concentration:
pOH = −log [OH−]
If the concentration of the hydroxide ion is 10−9 M, then the pOH of the
solution is +9.
From the equation
[H+][OH−] = 1.0 × 10−14 at 298 K
the following relationship can be derived:
pH + pOH = 14.00
In other words, the sum of the pH and pOH of an aqueous solution at 298 K
must always equal 14.00. For example, if the pOH of a solution is 9.00, then its
pH must be 5.00.