Preparation and Standardization of 0.1M Sodium Nitrite
Preparation: Weigh accurately 7.5 gm of Sodium Nitrite transfer it to 1000ml Volumetric Flask dissolve and dilute upto the mark with purified water and shake well.
Standardisation:
Method – I: Dissolve 0.3 g of sulphanilic acid in 50 ml of 2 M hydrochloric acid, add 3 g of potassium bromide, cool in ice and titrate with
the sodium nitrite solution determining the end-point potentiometrically.
Method – II: Dissolve 0.3 g of sulphanilamide in 50 ml of 2 M hydrochloric acid, add 3 g of potassium bromide, cool in ice and titrate with
the sodium nitrite solution determining the end-point potentiometrically.
Determine at least 3 set for this titration and calculate RSD and Mean of Molarity.
1 ml of 0.1 M sodium nitrite is equivalent to 0.01732 g of sulphanilamide and sulphanilic acid.
Calculation: = (Wt of STD × 0.1) / (BR × 0.01732)
Generally burrete reading for this titration is found about 17.3 ml.