pH is equivalent to the negative log of the concentration of
H in molarity, that is:
pH = - log [H]
so the concentration is:
8.05 = - log [H]
[H] = 8.91 x 10^-9 M
the absolute error is:
8.07 = - log [H’]
[H’] = 8.51 x 10^-9 M
absolute error = 8.91 x 10^-9 M - 8.51 x 10^-9 M = 0.4 x
10^-9 M
Therefore:
8.91 x 10^-9 M ± 0.4 x 10^-9 M
