Preparation and Standardization of 0.5 M Methanolic Hydrochloric Acid : Pharmaguideline

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Preparation and Standardization of 0.5 M Methanolic Hydrochloric Acid

Preparation and standardisation of 0.5 M Methanolic Hydrochloric Acid using anhydrous Sodium Carbonate and Methyl Red solution as indicator used in analysis of pharmaceutical ingredients.

Methanolic Hydrochloric Acid Solution Preparation

  • Take 40 ml of water in a 1000 ml volumetric flask.
  • Slowly add 43 ml of hydrochloric acid.
  • Cool and add methanol to volume.
  • Standardize the solution in the following manner.

Methanolic Hydrochloric Acid Solution Standardization

  • Weigh accurately about 800 mg of anhydrous sodium carbonate, previously heated at about 270°C for 1 hour.
  • Dissolve it in 100 ml of water and add 0.1 ml of methyl red solution.
  • Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink.
  • Heat the solution to boiling, cool and continue the titration.
  • Heat again to boiling and titrate further as necessary until the faint pink color is no longer affected by continued boiling.
  • 1 ml of 0.5 M hydrochloric acid is equivalent to 0.02650 g of Na2CO3.
  • Calculate the molarity of solution by the following formula:
             Na2CO3 in mg
M = --------------------------
          HCl in ml x 26.50
Also see: Determination of Shelf Life of Solutions in Laboratory

Ankur Choudhary is India's first professional pharmaceutical blogger, author and founder of, a widely-read pharmaceutical blog since 2008. Sign-up for the free email updates for your daily dose of pharmaceutical tips.
.moc.enilediugamrahp@ofni :liamENeed Help: Ask Question

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  1. sir i want to know how water is used to make methanolic HCl and if i want to prepare 0.1N methanolic HCl what will be the procedure for preparation and its standardization. please reply


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