Preparation and Standardization of 0.0167 M Potassium Dichromate

Potassium Dichromate Solution Preparation

• Weigh 4.9 g of potassium dichromate, previously powdered and dried in a desiccator for 4 hours.
• Dissolve in sufficient water to produce 1000 ml. Standardize the solution in the following manner.

Potassium Dichromate Solution Standardization

• To 20.0 ml of the solution add 1 g of potassium iodide and 7 ml of 2 M hydrochloric acid.
• Add 250 ml of water and titrate with 0.1 M sodium thiosulphate, using 3 ml of starch solution, added towards the end point of the titration, as indicator until the color changes from blue to light green.
• 1 ml of 0.1 M sodium thiosulphate is equivalent to 0.0049 g of K2Cr2O7.

Also see: Determination of Shelf Life of Solutions in Laboratory