Preparation and standardization of 0.1 N Sodium Hydroxide IH Volumetric Solution
Dissolve 4.2 g of NaOH in water and dilute to 1000 mL with water.
Weigh accurately about 0.5 g of anhydrous Potassium hydrogen phthalate previously powdered and dried at 120°C for two hours and dissolve in 75 mL of CO2-free water. Titrate against 0.1 N Sodium hydroxide potentiometrically.
Each 0.02042 g of Potassium hydrogen phthalate is equivalent to 1 mL of 0.1 N NaOH.
Normality (N) = [0.1 x Weight of Potassium hydrogen phthalate (in g)]/[ 0. 02042 x Titration reading (in mL)]
Limit: 0.1 N ± 5 % (0.0950 N – 0.1050 N)
3. STORAGE CONDITION:
Preserve in glass-stoppered bottles.