Chrominfo: Preparation and standardization of 0.1 M potassium iodate

Learn about the preparation and standardization of 0.1 M potassium iodate solution through a laboratory experiment or practical.

Aim:

To prepare and standardize 0.1 M potassium iodate solution using 0.1 M solution of sodium thiosulphate.

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, wash bottle, etc.

Chemicals: AR grade potassium iodate (KIO3), potassium iodide (KI), sulphuric acid (H2SO4), sodium thiosulphate (Na2S2O3), starch, etc.

Apparatus: Digital/analytical balance, and Ultrasonicator.

Click here to get the procedure.

Take 21.4 gm of previously dried potassium iodate in 500 ml of water. Once it has completely dissolved, make up the volume to 1000 ml.

All glassware should be cleaned and dried according to standard laboratory procedures.
Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
Remove air bubbles from the burette and adjust the reading to zero.
Take 25.00 ml of prepared solution of potassium iodate into 200 ml of water. In 20.00 ml of this solution, add 02.00 g of potassium iodide and 10.00 ml of 1M sulfuric acid.
Add 01.00 ml of the starch indicator.
Titrate the sample solution with 0.1M sodium thiosulphate until the endpoint is reached. The actual endpoint indicates by colorless to blue starch-iodine complex.
Properly record the readings of the burette.
To get accurate results, repeat the titration three times.
Take their mean and calculate the molarity of ferrous ammonium sulphate.
01 ml of 0.1M sodium thiosulphate is equivalent to 0.003566 gm of KIO3.