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Redox Reactions

High schoolChemistryNet-ionic redox stoichiometry with limiting reagents, oxidation states and formal electron-transfer accounting

Click a blue electron symbol to advance a reaction packet. Compare donor oxidation states, acceptor reduction and the amount limited by each reagent.

Zn → Zn²⁺Cu²⁺ → Cu0 → 22 → 0−−Electron bookkeeping

Progress through the limiting-reagent extent: 0%

Measurement notebook

Change the setup, test a prediction and save the result. Up to 12 snapshots are kept.

About this experiment

Advance a redox reaction in packets. Follow the donor and acceptor oxidation states while measuring reactants, products and the formal electron amount transferred.

Learning goals

  • Identify oxidation as an increase in oxidation state.
  • Match electrons lost with electrons gained.
  • Use stoichiometric coefficients to find the limiting reagent.

How to use it

  1. 1Choose zinc with copper ions and transfer one reaction packet at a time.
  2. 2Complete the limiting extent and compare donor loss with reduced product.
  3. 3Switch to copper with silver ions and test the two-to-one acceptor requirement.
  4. 4Use the iron and cerium ion pair and verify the one-electron bookkeeping.

The model

The maximum extent is set by the limiting reagent.
Each reaction extent transfers the balanced formal electron amount.
One copper atom supplies two electrons for two silver ions.

Assumptions

  • The selected reactions are ideal net-ionic stoichiometric transformations. No reaction rate or electrode potential is calculated.
  • The progress control is a fraction of the limiting-reagent extent, not physical time.
  • Blue electron symbols are formal bookkeeping. They are not free electrons moving through aqueous solution.
  • Counterions and solvent are omitted while net ionic charge and the tracked element amounts are conserved.

Try this in class

  1. Q1Why are two silver ions required for one copper atom?
  2. Q2Does a balanced net ionic charge imply that no electrons were transferred?

Frequently asked questions

Does oxidation always mean combining with oxygen?

No. In this bookkeeping activity it means an increase in oxidation state and formal electron loss.

Does the diagram show a physical electron beam between beakers?

No. The bridge is a bookkeeping diagram that links oxidation and reduction half-reactions.