Preparation and Standardization of 1M Hydrochloric Acid : Pharmaguideline

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Preparation and Standardization of 1M Hydrochloric Acid

Preparation and standardisation of 1 M Hydrochloric Acid solution using anhydrous Sodium Carbonate and Methyl Red solution as indicator used in pharmaceutical testing.

Hydrochloric Acid Solution Preparation

  • Dilute 85 ml of hydrochloric acid with water to produce 1000 ml.
  • Standardize the solution in the following manner.

Hydrochloric Acid Solution Standardization

  • Weigh accurately about 1.5 g 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 1M hydrochloric acid is equivalent to 0.05299 g of Na2CO3.
  • Calculate the molarity of solution by the following formula:
               Na2CO3 in mg
M = -----------------------------------------
       Hydrochloric Acid in ml x 52.99
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

5 comments: Post Yours! Read Comment Policy ▼

  1. why we should heat the solution ?

  2. Take hydrochloric acid sample in a 5 ml weighing bottle. Carefully transfer about 1 gm (weighing accurately) into a 100 ml conical flask containing 10 ml distilled water. Titrate with 1(N) sodium hydroxide solution taken in burette using methyl red as an indicator. 1 ml of 1(N) sodium hydroxide = 0.03646 gm. HCl.

    Assay of HCL (%) = Titre value (ml) x normality NaOH x 3.646/Weight of HCl sample taken (gm)

    Can I use above method for Hcl

  3. Can any one explain what is the meaning of this line, 1 ml of 1 M HCL Is equivalent to 0.05299 g of Na2co3

  4. Is this using for standardization 1.HCL tromethanine and please share me formula


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