Understanding Oxidation and Reduction
* Oxidation: Loss of electrons. The oxidation number of an element increases.
* Reduction: Gain of electrons. The oxidation number of an element decreases.
Applying the Concepts
1. Assign Oxidation Numbers:
* Cl₂: Each chlorine atom has an oxidation number of 0 (elemental state).
* NaBr: Sodium (Na) is +1, and bromine (Br) is -1.
* Br₂: Each bromine atom has an oxidation number of 0 (elemental state).
* NaCl: Sodium (Na) is +1, and chlorine (Cl) is -1.
2. Identify Changes:
* Bromine (Br): The oxidation number of bromine goes from -1 in NaBr to 0 in Br₂. This is a *loss* of electrons, so bromine is oxidized.
* Chlorine (Cl): The oxidation number of chlorine goes from 0 in Cl₂ to -1 in NaCl. This is a *gain* of electrons, so chlorine is reduced.
Summary
* Oxidation: Br⁻ → Br₂ (Bromine is oxidized)
* Reduction: Cl₂ → 2Cl⁻ (Chlorine is reduced)
The Reaction
The reaction is a classic example of a single displacement reaction. The more reactive chlorine displaces bromine from sodium bromide.
