Question

A solution of naoh(aq) contains 6.6 g of naoh(s) per 100.0 ml of solution. calculate the ph and the poh of the solution at 25 °c.

Answer 1

The  POh  and  Ph  of  the  solution  at  25 degrees is  calculated  as  follows

The  moles   of  the   solution =  6.6g/40(molar mass  of  NaOH)= 0.165 moles
concentration=  ( 0.165/100)  x1000= 1.65 M
NaOH in  solution  dissociated   as  follows
NaOH  --->  Na+    +  OH-
  POh= -  log  (OH-)

POh=  -log(1.65) =  -0.22

Ph=14-POh
that is  14 --0.22=14.22