Preparation and standardization of 0.1 M Hydrochloric acid BP Volumetric Solution

1.  PREPARATION:

Dilute 8.5 ml of Hydrochloric acid with sufficient water to produce 1000 ml.

2. STANDARDISATION:

Accurately weigh and dissolve 0.1 g of Anhydrous Sodium carbonate in 20 ml of water, add 0.1 ml of Methyl orange solution and titrate with the Hydrochloric acid until the solution becomes reddish yellow. Boil for 2 minutes and continue the titration until the reddish yellow colour is restored.

Each ml of 0.1 M Hydrochloric acid VS is equivalent to 5.30 mg of Na2CO3

Calculation:

Molarity (M) = [0.1 x Weight of Na2CO3 (in g)]/ [Titration reading (in ml) x 0.0053]

Limit: 0.1 M ± 5 % (0.0950 M – 0.1050 M)

3. PREPARATION OF INDICATORS / REAGENTS:

a. Methyl orange solution:

Dissolve 0.1 g of Methyl orange in 80 ml of water and add sufficient Ethanol (96 %) to produce 100 ml.

Sensitivity: A mixture of 0.1 ml of the solution and 100 ml of carbon dioxide free water is yellow. Not more than 0.1 ml of 1 M Hydrochloric acid VS is required to change the colour of the solution to red.

Colour change: pH 3.0 (red) to 4.4 (yellow)

4. STORAGE CONDITION:

Store in glass-stoppered bottles.

Scroll to Top