How to Prepared and Standardize of 0.5 N Potassium Hydroxide, Alcoholic Volumetric Solution.

How to Prepared and Standardize of 0.5 N Potassium Hydroxide, Alcoholic Volumetric Solution.

                                       

                                     

Preparation of 0.5 N Potassium Hydroxide,Alcoholic 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.

Potassium Hydroxide Reagent Grade, 

Mol Wt. :- KOH,  56.11

Hdrochloric Acid Volumetric Soliution (0.5 N),

Phenolphthalein Indicator,

Aldehyde Free Alcohol,

Phenolphthalein Indicator.

➤ Preparation.

Weigh 35 g of potassium hydroxide reagent grade in 100 ml beaker and dissolve in 20 ml of water. Transfer carefully to 1000 ml volumetric flask and make up to the volume with aldehyde free alcohol. Allow the solution to stand in a tightly stoppered bottle for 24 hours. Then quickly decant the clear supernatant liquid in to a suitable, tight container.

➤ Standardization.

Pipette out 25ml of 0.5 N / 0.5 M hydrochloric acid VS into a   250 ml conical flask. Dilute with 50 ml of water, add two drops of phenolphthalein solution, and titrate with alcoholic potassium hydroxide solution until a permanent pale pink colour is produced.

➤ Calculations.

                   ml , HCl  x N/M HCl

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

                             ml,  KOH