The oxidation state of carbon in the C2O4^2- ion, commonly known as the oxalate ion, is +3.
Understanding Oxidation States
An oxidation state (also known as an oxidation number) represents the hypothetical charge an atom would have if all bonds were purely ionic. It's a useful concept in chemistry for tracking electron transfer in chemical reactions, particularly in redox reactions. The sum of the oxidation states of all atoms in a neutral compound must equal zero, while in a polyatomic ion, the sum must equal the charge of the ion.
Calculating the Oxidation State of Carbon in C2O4^2-
The C2O4 entity is known as the oxalate ion, a polyatomic ion carrying a net charge of -2. In this ion, oxygen typically exhibits an oxidation state of -2. We can use this information to determine the oxidation state of carbon.
Step-by-Step Calculation:
- Identify the overall charge of the ion: The oxalate ion (C2O4^2-) has an overall charge of -2.
- Identify the known oxidation state of oxygen: Oxygen (O) in most compounds and ions has an oxidation state of -2.
- Set up the equation: Let 'x' be the oxidation state of carbon (C). Since there are two carbon atoms and four oxygen atoms in the C2O4^2- ion, the sum of their oxidation states must equal the ion's charge:
(2 × Oxidation State of C) + (4 × Oxidation State of O) = Overall Charge of Ion
(2 x) + (4 -2) = -2 - Solve for x:
2x - 8 = -2
2x = -2 + 8
2x = 6
x = 6 / 2
x = +3
Therefore, the oxidation state of each carbon atom in the oxalate ion (C2O4^2-) is +3.
Summary of Oxidation States in Oxalate Ion
| Element | Number of Atoms | Oxidation State per Atom | Total Oxidation State |
|---|---|---|---|
| Carbon | 2 | +3 | +6 |
| Oxygen | 4 | -2 | -8 |
| Total | -2 |
This calculation confirms that the sum of the individual oxidation states matches the overall charge of the oxalate ion. Oxalate ions are common ligands in coordination chemistry and play a role in biological processes, often forming salts with various metal ions.
