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





is a prominent Pharmaceutical Quality Assurance expert, consultant and the founder of Pharmaguideline. With over 22 years of hands-on experience in cGMP-compliant manufacturing environments, he specializes in establishing validation protocols, sterile area controls and data integrity systems. Ankur routinely interprets international regulatory frameworks (including FDA, EMA and ICH guidelines) to help global pharmaceutical professionals ensure strict regulatory compliance and operational excellence. Connect with Ankur on LinkedIn. Need Help: Ask Question

1 comment: Post Yours! Read Comment Policy ▼

  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

    ReplyDelete

Please don't spam. Comments having links would not be published.