1,000,000
gallons of water     =  Â
3785411.78 L
at pH = 4.45 ,  [H3O+] = 10^-pH = 10^-4.45 =
3.55*10^-5 M
     at pH = 7.8 , [H3O+] =
10^-pH = 10^-7.8 = 1.585*10^-8 M
the concentration of [H3O+] reduced =
(3.55*10^-5)-(1.585*10^-8 ) = 3.548415*10^-5 M
  concentration of [OH-] needed =
3.548415*10^-5 M
   concentration of NaOH needed
=Â Â 3.548415*10^-5 = W/mwt*1/V
                                              Â
3.548415*10^-5 = (w/40)*(1/3785411.78)
amount of NaOH needed = 5372.9 g
                                                Â
= 11.845 pound
