Balancing with Electrons
Part of the Oxidation and Reduction section of Coddy's Chemistry journey. Lesson 12 of 27.
Step 1: balance the atoms of the changing element. Step 2: add electrons until the charges match.
Al → Al³⁺ + 3e⁻
The right was +3, so three electrons go on the right.
O₂ + 4e⁻ → 2O²⁻
Two O²⁻ make −4, so four electrons go on the left.
Challenge
When aluminum metal reacts with an acid, each atom becomes an Al³⁺ ion. Balance the oxidation half-equation.
Try it yourself
Equation balancerBalance the equation
AlAl3+e−
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Oxidation and Reduction
3Half-Equations
Writing Half-EquationsBalancing with ElectronsHalf-Equations in AcidCombining Half-EquationsRecap - Permanganate