Answer:
pH before addition of KOH = 4.03
pH after addition of 25 ml KOH = 7.40
pH after addition of 30 ml KOH = 7.57
pH after addition of 40 ml KOH = 8.00
pH after addition of 50 ml KOH = 10.22
pH after addition 0f 60 ml KOH = 12.3
Explanation:
pH of each case in the titration given below
(6) After addition of 60 ml KOH
Since addition of 10 ml extra KOH is added after netralisation point.
Concentration of solution after addition 60 ml KOH is calculated by
M₁V₁ = M₂V₂
or, 0.23 x 10 = (50 + 60)ml x M₂
or M₂ = 0.03 Molar
so, concentration of KOH = 0.03 molar
[OH⁻] = 0.03 molar
pOH = 0.657
pH = 14 - 0.657 = 13.34
