Barium Iodide

Barium Iodide is an inorganic compound with the chemical formula \(BaI_2\). The compound exists as an anhydrous and a dihydrate (\(BaI_2 \cdot (H_2O)\)) form.

Structure and Formula

The IUPAC name of this inorganic compound is Barium iodide whose formula is \(BaI_2\) (anhydrous) & \(BaI_2 . 2H_2O\) (dihydrated).

Crystal structure of Barium Iodide (Anhydrous).
Crystal structure of BaI2 (Anhydrous). (Source)

The structure of the anhydrous form is Orthorhombic, with each Ba centre bound to nine iodide ligands and has a crystalline packing structure.

Physical Properties

Molecular weight (dihydrous)427.167 g/mol
Molecular weight(anhydrous)391.136 g/mol
Density1.79 g / cm3
Melting point711°C (anhydrous)
Decompostion740°C (dihydrate)
AppearenceWhite Orthorhombic crystals
Water solubility221g / 100ml (20°C)
SolubilitySoluble in ethanol, acetone
Crystal structureOrthorhombic

Chemical Properties

FlammabilityNon flammable
ToxicityToxic for humans
Standard enthalpy of formation-602.1 kJ . mol-1


It can be made by the reaction of barium and iodine molecules as metals and halogens are highly reactive. 

\(Ba + I_2  \rightarrow BaI_2\)

The reaction of potassium iodide with barium nitrate in the presence of water will yield dihydrate BaI2

\(KI (aq) + Ba(NO_3)_2 (aq) \rightarrow KNO_3 (aq) + BaI_2(aq)\)

(This a double displacement reaction and is reversible)


Barium iodide reacts with Potassium Bromide giving a yellow color precipitate.

\(KBr + BaI_2 \rightarrow KI(yellow ppt.) + BaBr_2\)

Barium sulfate formation,

\(BaI_2 + Na_2SO_4 \rightarrow BaSO_4 + 2NaI\)


  • It is used in the preparation of iodide compounds (has no direct medical use). 
  • It is also used for the preparation of barium dioxide and other important compounds of Iodine.


Like all other soluble salts of barium, BaI2 is also this hazardous and toxic.


What is the formula for Barium Iodide?

The formula for Barium Iodide(anhydrous) is \(BaI_2\) and Barium Iodide(dihydrous) is \(BaI_2\cdot 2(H_2O)\)

Is Barium Iodide covalent or ionic?

It is an ionic compound.

What is the color of Barium?

It is silvery gray; with a pale yellow tint.

More on Inorganic Compounds

Mohr’s Salt (Fe(SO4)(NH4)2(SO4)(H2O)6)Sodium Potassium Tartrate (C4H4O6KNa.4H2O)
Chlorine Trifluoride (ClF3)Sulfur Trioxide (SO3)
Sodium Sulfate (Na2SO4)Ammonium Bicarbonate ((NH4)HCO3)

Other Salts Of Barium

Barium Carbonate (BaCO3)Barium bromide (BaBr2)
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