Potassium iodide Definition
A white crystallinesolid, KI, with a strong bittertaste, soluble in water, ethanol, andacetone; cubic; r.d. 3.13; m.p. 681°C;b.p. 1330°C. It may be prepared bythe reaction of iodine with hot potassiumhydroxide solution followed by separation from the iodate (which isalso formed) by fractional crystallization.In solution it has the interestingproperty of dissolving iodine to formthe triiodide ion I3-, which is brown.Potassium iodide is widely used as ananalytical reagent, in photography,and also as an additive to table salt toprevent goitre and other disordersdue to iodine deficiency.


Potassium iodide  Usage 
1.      manufacture of photographic emulsions; in animal and poultry feeds to the extent of 10-30 parts per million; in table salt as a source of iodine and in some drinking water; also In animal chemistry. In medicine,potassium iodide is used to regulate the thyroid gland.

2. Potassium Iodide is a source of iodine and a nutrient and dietary supplement. it exists as crystals or powder and has a solubility of 1 g in 0.7 ml of water at 25°c. it is included in table salt for the preven- tion of goiter.Potassium Iodide is used primarily used in the treatment of radiation poisoning due to environmental contamination by iodine-131.

3.  Potassium iodide is a white crystal, granule or powder made by the reaction of iodine with hot potassium hydroxide solution followed by crystallization. It is very soluble in water, alcohol, and acetone. Potassium iodide was first used as the primary halide in Talbot's calotype process, then in the albumen on glass process followed by the wet collodion process. It was also used as a secondary halide in silver bromide gelatin emulsions.