Get the latest updates from us for free
Android App

Preparation and Standardization of 0.1 M Lithium Methoxide


Preparation and standardisation 0.1 M Lithium Methoxide solution using Benzoic Acid and Quinaldine red solution as indicator that is used in pharmaceutical analysis.

Lithium Methoxide Solution Preparation

•  Dissolve in small portions 0.7 g of freshly cut lithium in 150 ml of anhydrous methanol, cooling the flask during the addition of the metal.
•  When reaction is complete add sufficient toluene to produce 1000 ml.
•  If cloudiness or precipitation occurs, add sufficient anhydrous methanol to clarify the solution.
•  Standardise the solution immediately before use in the following manner.


Lithium Methoxide Solution Standardization


•  Weigh accurately about 0.25 g of benzoic acid, dissolved in 25 ml of dimethylformamide.
•  Titrate with lithium methoxide solution, using quinaldine red solution as the indicator and protecting the solution from atmospheric carbon dioxide throughout the titration.
•  Perform a blank determination and make any necessary correction.
•  1 ml of 0.1 M lithium methoxide is equivalent to 0.01221 g of C7H6O2.
•  Calculate molarity of solution by following formula:


                      C7H6O2 in mg
M = ------------------------------------------
         Lithium Methoxide in ml  x 12.21

Also see: Determination of Shelf Life of Solutions in Laboratory

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


Be the first to comment!

Post a Comment