Ferric Chloride(FeCl3) Properties(25 Facts You Should Know)

Ferric chloride, also known as iron trichloride, is an inorganic compound. It is sparingly soluble in water. Let us learn some facts related to ferric chloride.

Ferric chloride has multiple pharmaceuticals and industrial and laboratory applications. Ferric chloride is synthesized in industries by reacting scrap iron and dry chlorine at 500-700 oC. It is used in ministering sewage, etching copper during a redox reaction, making PCBs, and detecting phenolic compounds.

In this article, we will discuss different properties of Ferric Chloride like chemical classification, electronic configuration, oxidation state and reaction with acid, base, oxides, and metals etc.

FeCl3 IUPAC Name 

The IUPAC (International Union of Pure and Applied Chemistry) name of FeCl3 is Iron (III) chloride. 

FeCl3 Chemical Formula

FeCl3 is the chemical formula of Ferric chloride.

FeCl3 CAS Number

The CAS Number (authentic numeric identifier with upto10 digits) of FeCl3 is 7705-08-0.

FeCl3 ChemSpider ID

The ChemSpider ID (ChemSpider is a free chemical structure database) of FeCl3 is 22792.

FeCl3 Chemical Classification

FeCl3 is classified as a class 8 corrosive solid. It is a highly reactive material and should be handled with care.

FeCl3 Molar Mass

The molar mass of anhydrous FeCl3 is 162.204 g/mol, whereas the molar mass of hexahydrate FeCl3 is 270.295 g/mol.

FeCl3 Color

The color of FeCl3 is orange-to-brown-black compound.

FeCl3 Viscosity

The viscosity of FeCl3 is 12 cP (40% solution).

FeCl3 Molar Density

The molar density of FeCl3 is 1.1 g/mL.

FeCl3 Melting Point

The melting point of FeCl3 is 306 °C.

FeCl3 Boiling Point

The boiling point of FeCl3 is 315 °C.

FeCl3 State at Room Temperature

FeCl3 is a crystalline solid at room temperature.

FeCl3 Ionic Bond

FeCl3 forms ionic bonds. It possesses the tiniest FeCl3 repeating unit within the ferric chloride crystal lattice structure.

FeCl3 Ionic Radius

We can not determine the ionic radius of FeCl3 as we can only calculate the radius of a single atom. Moreover, the ionic radius of the ferric ion is 63 pm.

FeCl3 Electron Configurations

The electronic configuration refers to the electron distribution of a molecule or an atom in molecular or atomic orbitals. Let us discuss the electronic configuration of FeCl3.

The electronic configuration of ferric in FeCl3 is 1s2 2s2 2p6 3s2 3p6 4s2 3d6. In contrast, the electronic configuration of chlorine is 1s2 2s2 2p6 3s2 3p5.

FeCl3 Oxidation State

  • The Fe atom in FeCl3 is in a +3 oxidation state.
  • The Cl atom has a -1 oxidation state in FeCl3.

FeCl3 Acidity

FeCl3 is acidic in nature as it is a salt of strong acid and a weak base. Its pH value is less than 7, and it is corrosive to most metals and tissues.

Is FeCl3 Odourless

FeCl3 is not odorless. It possesses a faint hydrochloric acid odor. 

Is FeCl3 Paramagnetic

The presence of unpaired electrons indicates the paramagnetic characteristics of an element. Let us see if the FeCl3 contains an unpaired electron.

FeCl3 is paramagnetic in nature, because it contains unpaired electrons in its outermost valence shell, and on applying any external magnetic field, attracts each other and shows paramagnetic characteristics.

FeCl3 Hydrates

There are four hydrates of FeCl3 namely- FeCl3.2H2O, FeCl3.2.5H2O, FeCl3.3.5H2O and FeCl3.6H2O. These hydrates are powerful dehydrating agents. The different hydrates of FeCl3 are explained in the table below.

TypeMolecular FormulaStructural Formula
DihydrateFeCl3.2H2Otrans-[FeCl2(H2O)4][FeCl4]
UnnamedFeCl3.2.5H2Ocis-[FeCl2(H2O)4][FeCl4]·H2O
UnnamedFeCl3.3.5H2Ocis-[FeCl2(H2O)4][FeCl4]·3H2O
HexahydrateFeCl3.6H2Otrans-[FeCl2(H2O)4]Cl·2H2O
FeCl3 Hydrates

FeCl3 Crystal Structure

FeCl3 exists in a crystalline hexagonal, hR24 solid structure.

FeCl3 Polarity and Conductivity

  • FeCl3 is a polar molecule. It exhibits polarity due to the dipole moment, which originates from the high electronegativity difference between ferric and chlorine atoms, making FeCl3 polar.
  • FeCl3 is conductive, which follows parabolic pathway. The value of conductivity varies with the concentration.

FeCl3 Reaction with Acid

At low temperatures, FeCl3 reacts with an acid to form a red precipitate.

3CH3COOH + FeCl3 → (CH3COO)3Fe + 3HCl

FeCl3 Reaction with Base

FeCl3 reacts with a base to form a flock of Ferric hydroxide i.e Fe(OH)3, also written as Ferrihydrite, i.e FeO(OH), which is used in removing the suspended impurities.

3NaOH + FeCl3 → Fe(OH)3 + 3NaCl

FeCl3 Reaction with Oxide

FeCl3 reacts with oxides to form ferric oxides and corresponding salt. For Example, FeCl3 reacts with magnesium oxide to form ferric oxides and corresponding magnesium chloride.

2FeCl3 + 3MgO → Fe2O3 + 3MgCl2

FeCl3 Reaction with Metal

FeCl3 reacts with metal to form metal salt and ferrous chloride. It is corrosive to most metals and is widely used to etch in the branch of chemical etching, primarily in etching stainless steel and steel; but it is proficient in etching copper too.

FeCl3 + Cu → CuCl + FeCl2

Conclusion

FeCl3, also referred to as Iron (III) chloride or ferric chloride, is an orange-to-brown-black compound. It is a crystalline solid at room temperature and has a faint hydrochloric acid odor. It is a hexagonal, paramagnetic polar molecule and exists in the form of four hydrates.