The chemical formula of iodine is I₂.
Physical Properties of Iodine:
| Properties | Details |
| Physical state | Solid (at room temperature) |
| Color | Dark gray/purple |
| Odor | Faint, distinctive odor |
| Melting point | 113.7 °C (236.7 °F) |
| Boiling point | 184.3 °C (363.7 °F) |
| Density | 4.93 g/cm³ |
| Solubility | Slightly soluble in water; soluble in organic solvents |
| Crystal structure | Orthorhombic |
| Appearance | Shiny, crystalline solid |
| Conductivity | Poor electrical and thermal conductivity |
| Sublimation | Iodine sublimes directly from a solid to a gas |
Chemical Properties of Iodine:
| Properties | Details |
| Displacement reactions | Can displace less reactive halogens from their compounds |
| Oxidation state | -1, +1, +3, +5, +7 |
| Reaction with halogens | Reacts vigorously with fluorine to form iodine pentafluoride (IF5) |
| Reaction with hydrogen | Forms hydrogen iodide (HI) |
| Reaction with metals | Forms ionic compounds (e.g., iodides) |
| Reaction with oxygen | Combines with oxygen to form iodine oxides (e.g., iodine pentoxide, I2O5) |
| Reaction with reducing agents | Can be reduced to iodide ions |
| Reaction with sulfur | Forms sulfur iodides |
| Reactivity | Moderately reactive |
| Stability | Relatively stable in air, but can slowly sublime |
Reaction of iodine with Transition Metal
| Transition Metal | Reaction with Iodine |
| Titanium (Ti) | Ti + 2I₂ react and convert into TiI₄ |
| Iron (Fe) | 2Fe + 3I₂ react and convert into 2FeI₃ |
| Cobalt (Co) | Co + I₂ react and convert into CoI₂ |
| Nickel (Ni) | Ni + I₂ react and convert into NiI₂ |
| Copper (Cu) | Cu + I₂ react and convert into CuI₂ |
| Silver (Ag) | 2Ag + I₂ react and convert into 2AgI |
| Palladium (Pd) | Pd + I₂ react and convert into PdI₂ |
| Platinum (Pt) | Pt + 2I₂ react and convert into PtI₄ |
| Gold (Au) | 2Au + 3I₂ react and convert into 2AuI₃ |
Reaction of iodine with Non-Transition Metal
| Non-Transition Metal | Reaction with Iodine |
| Aluminum (Al) | 2Al + 3I₂ react and convert into 2AlI₃ |
| Zinc (Zn) | Zn + I₂ react and convert into ZnI₂ |
| Tin (Sn) | Sn + 2I₂ react and convert into SnI₄ |
| Lead (Pb) | Pb + I₂ react and convert into PbI₂ |
| Antimony (Sb) | Sb + 3I₂ react and convert into SbI₃ |
| Bismuth (Bi) | Bi + 3I₂ react and convert into BiI₃ |
| Aluminum (Al) | 2Al + 3I₂ react and convert into 2AlI₃ |
| Selenium (Se) | Se + I₂ react and convert into SeI₂ |
| Tellurium (Te) | Te + I₂ react and convert into TeI₂ |
Reaction of iodine with Non-Metal Element
| Non-Metal Element | Reaction with Iodine |
| Hydrogen (H₂) | H₂ + I₂ ⇌ 2HI (reversible reaction) |
| Carbon (C) | no product |
| Nitrogen (N₂) | no product |
| Oxygen (O₂) | no product |
| Phosphorus (P₄) | P₄ + 6I₂ react and convert into 4PI₃ |
| Sulfur (S₈) | S₈ + 4I₂ react and convert into 4SI₂ |
| Chlorine (Cl₂) | Cl₂ + 2I₂ react and convert into 2ICl |
| Bromine (Br₂) | Br₂ + 2I₂ react and convert into 2IBr |
| Fluorine (F₂) | no product |
Reaction of iodine with Metalloid
| Metalloid | Reaction with Iodine |
| Boron (B) | no product |
| Silicon (Si) | no product |
| Germanium (Ge) | Ge + 2I₂ react and convert into GeI₄ |
| Arsenic (As) | As + 3I₂ react and convert into AsI₃ |
| Antimony (Sb) | Sb + 3I₂ react and convert into SbI₃ |
| Tellurium (Te) | Te + I₂ react and convert into TeI₂ |
Reaction of iodine with Lanthanide Element
| Lanthanide Element | Reaction with Iodine |
| Lanthanum (La) | La + 2I₂ react and convert into LaI₃ |
| Cerium (Ce) | Ce + 2I₂ react and convert into CeI₄ |
| Praseodymium (Pr) | Pr + 2I₂ react and convert into PrI₄ |
| Neodymium (Nd) | Nd + 2I₂ react and convert into NdI₄ |
| Promethium (Pm) | No stable isotopes |
| Samarium (Sm) | Sm + 2I₂ react and convert into SmI₄ |
| Europium (Eu) | Eu + 2I₂ react and convert into EuI₄ |
| Gadolinium (Gd) | Gd + 2I₂ react and convert into GdI₄ |
| Terbium (Tb) | Tb + 2I₂ react and convert into TbI₄ |
| Dysprosium (Dy) | Dy + 2I₂ react and convert into DyI₄ |
| Holmium (Ho) | Ho + 2I₂ react and convert into HoI₄ |
| Erbium (Er) | Er + 2I₂ react and convert into ErI₄ |
| Thulium (Tm) | Tm + 2I₂ react and convert into TmI₄ |
| Ytterbium (Yb) | Yb + 2I₂ react and convert into YbI₄ |
| Lutetium (Lu) | Lu + 2I₂ react and convert into LuI₃ |