Preparation and standardization of 0.5 N Hydrochloric acid USP Volumetric Solution

1.  PREPARATION :

To a 1000 ml volumetric flask containing 40 ml of water slowly add 43 ml of Hydrochloric acid. Cool, and add water to volume.

2. STANDARDISATION :

Accurately weigh about 2.5 g of Tromethamine dried according to the label instructions. Dissolve in 50 ml of water, and add 2 drops of Bromocresol green TS. Titrate with 0.5 N Hydrochloric acid to a pale yellow endpoint.

Each 60.57 mg of Tromethamine is equivalent to 1 ml of 0.5 N Hydrochloric acid.

Calculation :

Normality (N) = [Weight of Tromethamine (in g)]/[ 0.12114 x Titration Reading (in ml)]                                           

Limit : 0.5 N ± 5 % (0.4750 N – 0.5250 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.