How to prepare and Standardize 0.1 N Sodium hydroxide volumetric solution.

How to prepare and Standardize 0.1 N Sodium hydroxide volumetric solution.

                                                                

Preparation of  0.1 N Sodium hydroxide  volumetric solution.

➤ Glass ware and instruments required.

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

 ➤ Reagents required.

Sodium hydroxide.
Molecular wt NaOH , 40.0
Potassium hydrogen phthalate primary standard. (Previously dried for 2 hour at 120°C)
Phenolphthalein indicator.

➤ Preparation.

Weigh 4.2 g sodium hydroxide pallets reagent grade in beaker, add 150 ml of carbon dioxide free water. Cool to room temperature. Filter through filter paper and transfer to 1000 ml volumetric flask. Dilute up to the mark with same solvent and transfer to tight polyolefin container.

➤ Standardisation. 

Accurately weigh about 0.5 g potassium hydrogen phthalate PS,  previously crushed lightly and dried for 2 hour at 120°,   in 250 ml conical flask. Dissolve in 100 ml carbon dioxide free water. Add 2 drops of phenolphthalein indicator solution. Titrate with 0.1 N / 0.1 M sodium hydroxide till the solution becomes permanent pink. Note this final end point as burette reading in ml.

➤ Calculations.

                                  g  KHC₈H₄O₄  x  0.1

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

                         0.02042  x   Burette reading in ml 

How to Prepared and Standardize of 0.05 N Potassium Iodate Volumetric Solution.

How to Prepared and Standardize of 0.05 N Potassium Iodate Volumetric Solution.

                                                                 

                                                            

                                                               

Preparation of 0.05 N Potassium Iodate 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 Iodate Reagent grade,

Molecular Wt. :- KIO₃,  214.0

Potassium Iodide,

Sulphuric Acid Dilute, 

Sodium thiosulphate Volumetric Solution (0.05M),

Starch Solution.

➤ Preparation.

Weigh and transfer about 10.7 g of potassium iodate reagent grade into 1000 ml volumetric flask. Dissolve it in sufficient water and make up to the mark. Filter the solution, if it is not clear.

➤ Standardization.

Pipette out 25 ml of 0.05 M potassium iodate solution into 100 ml volumetric flask, and make up with water. To 20 ml of this solution, add 2 g of potassium iodide, and 20 ml of dilute sulphuric acid. Titrate with 0.1 M sodium thiosulphate VS using 1 ml starch solution, added towards end of titration, as an indicator.  End point is blue to colourless.

➤ Calculations.

                           g KIO₃  x  0.005 x 20 x 25

 M= ----------------------------------------------------------------------

                     0.03566 x Burette Reading in ml x 1000