Standardization and Preparation of 1 N Sulfuric acid (H2SO4) in pharma

Preparation Of 2 N Sulfuric Acid:

Preparation of 1 N Sulfuric acid:

Preparation of 1 N sulfuric acid and lower concentration solutions can be prepared by referring to the below table:

Strength of volumetric soln.Quantity of Sulfuric Acid in mLMakeup with water in mL
1 N271000
0.5 N13.51000
0.1 N2.71000
0.05 N1.41000
0.025 N0.751000
0.02 N0.61000
0.01 N0.31000
Preparation of different concentration solution

Standardization of Sulfuric acid:

Reagent required:

95% V/V Alcohol: Mix 95 ml of absolute alcohol with 5 ml of water.

Bromocresol green solution: Dissolve 50mg of Bromocresol green in 100 ml of ethanol (95%).


  1. Dry the Tromethamine at 105°C for 3 hrs.
  2. Cool to room temperature and crush it.
  3. Weigh accurately about 10gm of dried Tromethamine in 50 ml volumetric flask.
  4. Add 2 ml of bromocresol green solution.
  5. Titrate the solution with sulfuric acid.
  6. The pale yellow color will produce at the end point.

Calculation of 1 N sulfuric acid solution:

Calculation of Normality of 1N sulfuric acid solution can be done by the following formula;

W x 1000

Normality of 1 N Sulfuric acid = —————–

121.14 x V

Preparation of 1 N sulfuric acid solution

Alternate preparation of 0.01 N Sulfuric acid:

Preparation: Transfer 10 ml of 1 N sulfuric acid volumetric solution to a 1000 ml of volumetric flask and dilute to volume with water.

Standardization: Weigh accurately about 0.05g of Tromethamine dried and dissolve to 50ml with water.

Perform Potentiometric Titration due to lower concentration.

Titrate 0.01 N Sulfuric acid solution potentiometrically by using pH glass electrode.


Refer to the above-mentioned formula for the preparation of 1 N Sulfuric acid.

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