${H^ + } = \sqrt {Kc} $ $ = \sqrt {4.5 \times {{10}^{ - 3}} \times 1.7 \times {{10}^{ - 10}} \times .01} $
$ = 0.87 \times {10^{ - 7}}$$pH = - \log \;0.87 \times {10^{ - 7}}$$ = 7 - 0.93 = 6.1$.
${H_2}{O_2}\, + \,{H_2}O\, \rightleftharpoons \,{H_3}{O^ + }\, + \,HO_2^ - $