Iodine VS

I₂ = 253.8

For a 0.5m solution Dissolve 127 g of iodine and 200 g of potassium iodide in sufficient water to produce 1000 mL.

Ascertain its exact concentration in the following manner. To 2 mL of the solution add 1 mL of 2m acetic acid and 50 mL of water. Titrate with 0.1m sodium thiosulfate VS using starch solution as indicator. Each mL of 0.1m sodium thiosulfate VS is equivalent to 12.69 mg of I.

Store protected from light.

For a 0.05m solution Dissolve 12.7 g of iodine and 20 g of potassium iodide in water and dilute to 1000.0 mL with the same solvent.

Standardisation. To 10.0 mL of the iodine solution add 1 mL of dilute acetic acid and 40 mL of water. Titrate with 0.1 M sodium thiosulfate, determining the end-point potentiometrically (2.2.20) or using starch solution as indicator.

Store protected from light.

For a 0.01m solution Add 0.3 g of potassium iodide to 20 mL of 0.05m iodine VS and add sufficient water to produce 100 mL.