Preparation and standardization of 1 N Hydrochloric acid USP Volumetric Solution
1. PREPARATION :
Dilute 85 ml of Hydrochloric acid with water to 1000 ml.
2. STANDARDISATION :
Accurately weigh about 5.0 g of Tromethamine, previously dried at 105°C for 3 hours. Dissolve in 50 ml of water, and add 2 drops of Bromocresol green TS. Titrate with 1 N Hydrochloric acid to a pale yellow endpoint.
Each 121.14 mg of Tromethamine is equivalent to 1 ml of 1 N Hydrochloric acid.
Normality (N) = [Weight of Tromethamine (in g)]/[ 0.12114 x Titration Reading (in ml)]
Limit : 1 N ± 5 % (0.9500 N – 1.0500 N)
3. PREPARATION OF INDICATORS / REAGENTS :
a. 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.