What is the Difference Between Ferrous and Ferric Oxide

ferrous and ferric oxide


The smallest idiosyncrasies can make a world of difference. Especially in the world of chemistry. There are 118 known elements on Earth that make more than nine million unique organic compounds. All it takes is a small change at the atomic level to move from one compound to the next. 

Take for example two commonly confused oxygen compounds of iron, ferrous oxide (FeO) and ferric oxide (Fe2O3). They are very similar but the big difference between them comes down to the oxidation state of their iron. Here, we will go down to the atomic level to examine the difference between ferrous oxide and ferric oxide. But in order to fully understand the difference, we need to understand oxidation. 


Oxidation occurs when a chemical reaction causes electrons to move. When a substance loses electrons we say that the substance has been oxidized. But oxidation is not like flipping a switch on or off. It occurs on a spectrum. To talk about the spectrum of oxidation a substance can experience, we have the term “oxidation state.” The oxidation state is the level of oxidation a substance has experienced and is expressed through an oxidation number. 


So, a substance’s oxidation number refers to the total number of electrons its atoms lose in bonding. Substances that go through an oxidation reaction get a number added to their name to note the loss and indicate their ability to bond with other atoms with electrons to spare.  


The iron in ferrous oxide and ferric oxide go through an oxidation reaction. To find out how many electrons the iron in ferrous oxide and ferric oxide lose when bonding, you need only look to their common names. 


Ferrous oxide, commonly known as iron(II) oxide contains iron that lost 2 elections in the oxidation process. So it is able to bond with other atoms that have an extra 2 electrons to share. Ferric oxide, is commonly known as iron(III) oxide. It contains iron that lost 3 elections and can take an extra 3 electrons with bonding with other atoms. 


There are numerous iron compounds, each with different roles in nature. We even need iron as part of our diets. Despite what may seem an almost trivial difference at the atomic level, the difference in the oxidation state between ferrous oxide and ferric oxide means that they each play unique roles in the world. 


Ferrous oxide comes as a black powder and, surprisingly, contains ferric oxide. It is used to produce numerous materials like plastics, heat-absorbing glass, paper, ceramics, and even rubber. Special high purity iron oxides are used to produce a type of ceramic magnet called ferrites, used in electronics like speakers, TVs, and computer memory cores. 


Ferric oxide, also known as hematite, is a reddish-brown powder. It is FDA approved for cosmetic use, even around the eyes. But ferric oxide is most helpful in the iron and steel industries. It is the primary source for the iron used to create the entire industrialized world. 


Though there are countless applications for both ferrous oxide and ferric oxide, Noah Technologies can help you obtain the right iron compound, in the purity and granulation you need to make your project a success. Discover a wealth of iron compounds in our massive online catalog. To speak with a qualified chemist about custom chemicals and bulk ordering contact us today!




Noah Technologies provides clients the purest chemicals. Purchase these chemicals directly from our massive online catalog. To speak with a qualified chemist about custom chemicals and bulk ordering contact us today!


Ferrous Oxide

IRON (II) OXIDE, 99.9% pure, -10 mesh, (Ferrous Oxide), FeO


Ferric Oxide

IRON (III) OXIDE, ANHYDROUS, 99.9% pure, -325 mesh, < 3 microns average, (Ferric Oxide, Anhydrous), Fe2O3


IRON (III) OXIDE, ANHYDROUS, 99.95% pure, -325 mesh, typ. 0.3 micron, (Ferric Oxide, Anhydrous), Fe2O3


IRON (III) OXIDE, HYDRATE, 99% pure, -325 mesh, (Ferric Oxide, Hydrate), Fe2O3.xH2O