Ferric oxide: Polarity and Application

Description of Ferric oxide

Ferric oxide, also known as iron(III) oxide, is an amphoteric iron oxide with the chemical formula Fe2O3. It exhibits acidic and basic properties. It is an inorganic compound. It is also known as hematite or red iron oxide. This compound occurs naturally in rocks of all ages. It appears as a reddish brown solid. It is odourless. It has a pH of 7.

Polarity of Ferric oxide

Fe2O3 is an ionic compound. The electronegativity difference between iron and oxygen atoms is 1.6, which corresponds to the electronegativity difference of a polar covalent bond. Therefore, Fe2O3 has a polar covalent bond and the compound has ionic properties. The difference in hybridisation results in unequal bond angles for O-Fe-O and Fe-O-Fe. The shared pair of electrons between the Fe and O are more attracted towards the O atom as it has a higher electronegativity than Fe. Therefore the dipole vectors are towards the oxygen atoms. Due to different bond angles, the dipole moment vectors do not cancel and have some value of net dipole moment. Therefore the molecule is polar in nature. Hence we say that Fe2O3is a polar compound.

Ferric oxide is not soluble in water, but is readily soluble in strong acids such as hydrochloric and sulfuric acids. It also dissolves well in chelating agent solutions such as EDTA and oxalic acid.

Application of Ferric oxide

Ferric oxide (Fe2O3) is used as a pigment and/or UV blocker in paints and coatings, inks, plastics, rubber products and glass. It is also used as a polishing agent for glass, diamonds and precious metals. The compound is also utilised as a component in magnets, as a dental abrasive and as a process regulator or catalyst in the manufacture of other products.