Solution:
From \(\mathrm{H}_{2} \mathrm{O},\left[\mathrm{H}^{2}\right]=1 \times 10^{-7} \mathrm{M}\)
From \(H C I,\left[H^{+}\right]=1 \times 10^{-8} M\)
Total \(\left[\mathrm{H}^{+}\right]=\left(1 \times 10^{-7}+1 \times 10^{-8}\right) \mathrm{M}\)
\(=\left(1 \times 10^{-7}+0.1 \times 10^{-7}\right) \mathrm{M}\)
\(=1.1 \times 10^{-7} \mathrm{M}\)
\(p H=-\log \left(1.1 \times 10^{-7}\right)=6.9586\)
