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9701 AS Chemistry/ Topic 6 Electrochemistry/ 5 interactive simulations/ drag to rotate 3D scenes

Electrochemistry and redox, made interactive

Five simulations covering Topic 6: oxidation numbers with the rules that fix them, electron transfer between a metal and a solution in 3D, building a redox equation from half-equations, tracking who is oxidised and who is reduced including disproportionation, and a preview of electrolysis.

1. Oxidation numbers 6.1

Oxidation numbers are a bookkeeping system for electrons. Pick a species and see each atom's oxidation number, which rule fixed it, and how the numbers add up to the overall charge.

Species

Rules in order: elements 0; F always −1; group 1 +1, group 2 +2; H +1 (−1 in metal hydrides); O −2 (−1 in peroxides, +2 in OF₂); the numbers add up to the charge on the species.

2. Electron transfer: zinc in copper(II) sulfate 3D · 6.1

Redox is electron transfer. When zinc is dipped into copper(II) sulfate, zinc atoms give up two electrons each and dissolve as Zn²⁺, while Cu²⁺ ions take those electrons and settle on the metal as copper atoms. Watch the electrons cross and the oxidation numbers change.

drag to rotate · press Start to run the reaction

Reaction

OXIDATION (loses e⁻)
REDUCTION (gains e⁻)
OXIDISING AGENT
REDUCING AGENT

3. Building a redox equation from half-equations 6.1

Write the oxidation and reduction half-equations, multiply so the electrons match, then add. Choose a pair and step through the working.

Half-equations

Balance each half-equation for atoms with H₂O and H⁺ (acidic conditions), then for charge with electrons. The electrons lost must equal the electrons gained.

4. Who is oxidised, who is reduced? 6.1

Track the oxidation numbers across an equation. An increase means oxidation; a decrease means reduction. The species that is reduced is the oxidising agent, and vice versa. Some reactions do both to the same element: disproportionation.

Reaction

5. Electrolysis: redox driven by a power supply 3D · beyond AS

Electrolysis is redox in reverse: the supply pushes electrons into the cathode, where cations are reduced, and pulls them out of the anode, where anions are oxidised. This is A Level (topic 20) content, included here because it is the natural end of the redox story.

drag to rotate · electrons flow through the wire, ions through the liquid

Electrolyte

1.5 A
CATHODE (−)
ANODE (+)
TheLucidSTEM · Cambridge International AS Level Chemistry 9701 · Topic 6 Electrochemistry. Every scene runs in the browser; drag to rotate 3D scenes, wheel to zoom. Values are standard textbook data rounded for teaching.

About this lab: Electrochemistry

Oxidation numbers and the rules that fix them, electron transfer from zinc to copper ions in 3D, combining half-equations into a balanced redox equation, tracking oxidation numbers across reactions including disproportionation, and a 3D electrolysis cell with ions and electrons moving.

Five simulations covering Topic 6: oxidation numbers with the rules that fix them, electron transfer between a metal and a solution in 3D, building a redox equation from half-equations, tracking who is oxidised and who is reduced including disproportionation, and a preview of electrolysis.

Electrochemistry is a free, browser-based simulation for Cambridge International AS & A Level Chemistry 9701 (topic 6 Electrochemistry). The same ideas are examined in Cambridge IGCSE Chemistry 0620 (topic 6 Chemical reactions, topic 4 Electrochemistry, topic 9 Metals). The course is assessed in Paper 1 (Multiple Choice (AS)), Paper 2 (AS Structured), Paper 3 (Advanced Practical), Paper 4 (A Level Structured), Paper 5 (Planning, Analysis, Evaluation). Syllabus for examination in 2025-2027. There are 5 tabs, each a self-contained experiment with its own controls and live readings, and nothing to install: it runs on a laptop, tablet or classroom projector.

Syllabus coverage

Full syllabus map: AS Level Chemistry 9701 topic 6.

How to use this simulation

  1. 1. Oxidation numbers. Oxidation numbers are a bookkeeping system for electrons.
  2. 2. Electron transfer: zinc in copper(II) sulfate. Redox is electron transfer.
  3. 3. Building a redox equation from half-equations. Write the oxidation and reduction half-equations, multiply so the electrons match, then add.
  4. 4. Who is oxidised, who is reduced? Track the oxidation numbers across an equation.
  5. 5. Electrolysis: redox driven by a power supply. Electrolysis is redox in reverse: the supply pushes electrons into the cathode, where cations are reduced, and pulls...
  6. The buttons at the end of the tab strip give the scene the whole window (Full screen, Hide controls) and, on a dark stage, a projector-friendly palette (Light scene). Many scenes also have drag handles: drag them to change the set-up directly.

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