• British Pharmacopoeia Volume V
  • Appendices
  • Appendix I B. Volumetric Reagents and Solutions
  • Volumetric Solutions

Iodine VS

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 20 g of potassium iodide in the minimum amount of water, add 12.7 g of iodine, allow to dissolve and dilute to 1000 mL with water.

Ascertain its exact concentration as described above but using 20 mL of the solution being examined and 30 mL of water.

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.