How to prepare and Standardize 0.1 N Ammonium Thiocynate acid volumetric Solution.

How to prepare and Standardize 0.1 N Ammonium Thiocynate acid volumetric Solution.

                                                                  

                   

                                                    

Preparation of 0.1 N Ammonium Thiocynate volumetric solution.

➤ Glass ware and instruments required.

Beaker, Glass stirrer, Graduated Pipettes, Graduated cylinder, Analytical balance, Sucker, Volumetric flask, Burette, Conical flask, Fume hood.

 

➤ Reagents required.

Ammonium Thiocynate Reagent grade

Molecular Wt. NH4SCN, 76.12

Silver Nitrate volumetric solution

Nitric Acid 

Ferric ammonium sulphate Solution

➤ Preparation.

Weigh about 8 g of ammonium thiocynate reagent grade in 1000 ml in 1000 ml volumetric flask. Dissolve and dilute with water. Filter the solution, if it is not clear.

➤ Standardisation.

Pipette out 25 ml of standard 0.1 N silver nitrate VS into glass stoppered flask. Dilute with 50 ml of water, then add 2 ml of nitric acid and 2 ml of ferric ammonium sulphate solution, and titrate with the ammonium thiocynate solution to the first appearance of red brown colour. 


➤ Calculations.

                              ml   AgNO₃  x  N / M  AgNO₃

N / M = ----------------------------------------------------------------------

                       ml  NH₄SCN solution  [ Burette reading in ml ]