more Reading

By the finish of gen bsci-ch.orgistry, calculating oxidation states of different metals should be nice familiar. Here’s what you do. Take it a usual compound – (FeCl_3), because that instance. Law every bond in between the metal and also a different atom as if it to be an ionic bond. That way the more electronegative facets (like chlorine, say, or oxygen) bear an adverse charges, and the less electronegative element (such together the metal) bear the confident charge.

You are watching: What is the oxidation number of carbon in co2

If the compound is neutral, the amount of the oxidation states also has to it is in neutral. (If the compound has a charge, you adjust the oxidation states as necessary so the their sum equates to the charge).


Now here’s a funny exercise. Shot applying the exact same rules to carbon. It’s walking to feeling a small bit weird. Why? because there space two key differences:

First, carbon is often an ext electronegative (2.5) than some of the atom it’s bound come (such as H, 2.2). For this reason what execute you do in this case? Secondly, unlike metal-metal bonds, carbon-carbon bonds are ubiquitous. So just how do you resolve them?

Two answers.

In a C-H bond, the H is treated as if it has actually an oxidation state of +1. This method that every C-H bond will certainly decrease the oxidation state of carbon by 1. Any kind of two bonds in between the same atom do not impact the oxidation state (recall the the oxidation state of Cl in Cl-Cl (and that of H in H-H) is zero. For this reason a carbon attached come 4 carbons has actually an oxidation state that zero.

So unequal metals, i m sorry are practically always in a confident oxidation state, the oxidation state the carbon have the right to vary widely, native -4 (in CH4) come +4 (such together in CO2). Below are some examples.


(Don’t forget the this is dubbed a “formalism” for a reason. The charge on the carbon is no really +4 or –4. However the oxidation state formalism helps us save track of where the electrons space going, which will certainly come in handy an extremely soon).

See more: Why Do Chows Have Blue Tongues ? 6 Dogs With Black Tongues

With an expertise of how to calculate oxidation states on carbon, we’re all set for the following step: understanding changes in the oxidation state at carbon, v reactions known as oxidations (where the oxidation state is increased), and also reductions (where the oxidation state is reduced). More on that next time.

The libraries arePowered by MindTouch®and are supported by the room of education Open Textbook Pilot Project, the UC Davis Office the the Provost, the UC Davis Library, the California State university Affordable discovering Solutions Program, and Merlot. We likewise acknowledge previous national Science foundation support under give numbers 1246120, 1525057, and also 1413739. Uneven otherwise noted, contents is licensed byCC BY-NC-SA 3.0. Legal. Have actually questions or comments? For much more information call us atinfo