Preparation and standardization of 0.025 mol/L Sulphuric acid [0.05 N Sulphuric acid USP] Volumetric Solution
Transfer 1.4 mL of Sulfuric acid to a 1000 mL volumetric flask containing about 500 mL of water. Cool and dilute with water to volume.
Accurately weigh about 0.25 g of Tromethamine, dried according to label instructions or, if this information is not available dried at 105°C for 3 hours.
Dissolve in 50 mL of water and add 2 drops of Bromocresol green TS.
Titrate with the Sulfuric acid solution to a pale yellow end point.
Each 6.057 mg of Tromethamine is equivalent to 1 mL of 0.025 mol/L Sulphuric acid.
Molarity = [0.025 x wt. of Tromethamine (mg)]/[ 6.057 x Titration Reading]
Limit: 0.025 M ± 5 % (0.0238 M – 0.0263 M)
3. PREPARATION OF INDICATORS / REAGENTS:
Bromocresol green TS :
Dissolve 50 mg of Bromocresol green in 100 mL of Alcohol, and filter if necessary.
4. STORAGE CONDITION:
Store in glass-stoppered bottles.