Oxidation Examples in Chemistry

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Oxidation.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

The loss of electrons by an atom, ion, or molecule during a chemical reaction, resulting in an increase in its oxidation state. Oxidation always occurs simultaneously with reduction in a redox pair.

Giving away electrons. Originally meant 'gaining oxygen' but it's broader.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: OIL RIG: Oxidation Is Loss of electrons — always paired with reduction in a redox reaction.

Common stuck point: Oxidation doesn't require oxygen — it's defined by electron loss, not by reacting with oxygen gas.

Sense of Study hint: When identifying oxidation in a reaction, track electron movement. First assign oxidation numbers to each atom before and after the reaction. Then find which atoms increased in oxidation number — those were oxidized. Finally, remember OIL RIG: Oxidation Is Loss of electrons.

Worked Examples

Example 1

easy
In the reaction 2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO}, identify which species is oxidized.

Solution

  1. 1
    Mg goes from oxidation state 0 (element) to +2 (in MgO).
  2. 2
    An increase in oxidation number means the species has lost electrons.
  3. 3
    Therefore, Mg is oxidized: \text{Mg} \rightarrow \text{Mg}^{2+} + 2e^-.

Answer

\text{Mg is oxidized (0 → +2)}
Oxidation is the loss of electrons (OIL RIG: Oxidation Is Loss). The substance that is oxidized serves as the reducing agent because it provides electrons to the other reactant.

Example 2

medium
In the reaction \text{Zn} + \text{Cu}^{2+} \rightarrow \text{Zn}^{2+} + \text{Cu}, write the oxidation and reduction half-reactions.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
Is iron rusting an example of oxidation? Explain.

Example 2

medium
In the reaction \text{CuO} + \text{H}_2 \rightarrow \text{Cu} + \text{H}_2\text{O}, which substance is oxidized?
← Back to Oxidation Practice Mode

Background Knowledge

These ideas may be useful before you work through the harder examples.

electronion