Iodine is a
nonmetallic halogen element in Group 17 of periodic table; atomic number 53;
atomic mass 126.9; melting point ca 114 C; boiling point ca 184 C; specific
gravity 4.93 g/cm3; oxidation states: 7,5,1,-1; [Kr] 4d10 5s2 5p5. Iodine is a
nearly black poisonous, corrosive solid at room temperature and readily sublimes
to a deep violet vapour, the colour of which is responsible for its name from
Greek. It is insoluble in water, soluble in common solvents. Iodine is required
in small amounts in human body for the function of the thyroid gland. Iodine
forms many important compounds of iodine such as iodine(V)oxide, potassium
iodide, iodine trichloride and iodoform of an Iodine containing organic
compound.
Iodine monochloride,
an interhalogen compound, is used as an iodinating agent.
The iodinated compounds are employed in many application, for example, as
solvents, intermediates for numerous chemicals, dyes, fumigants, sterilants, X-ray
contrast media, antiseptics and pharmaceuticals. Iodine monochloride is used
in Wijs' solution to determine iodine numbers. |