Hydroxide ion concentration, [OH] = 2.15*10-4
                                       Â
POH = - Log[OH]
                                              Â
= - Log[2.15*10-4]
                                   Â
  POH = 3.67
But
,                              Â
PH = 14 - POH
                                                         Â
= 14 -3.67
                                    Â
PH = 10.3