ChemistryMapUnit 8, Electrochemistry
8.1Voltaic cells
Build a cell from two metals, read its voltage, and see oxidation and reduction at each electrode.
Build a voltaic cell
Choose two half-cells. Follow the electrons and inspect each electrode.
Standard cell potential0.00 V
CircuitOpen
- Anode: oxidation
- Zn(s) → Zn²⁺(aq) + 2e⁻
- Cathode: reduction
- Cu²⁺(aq) + 2e⁻ → Cu(s)
- Balanced cell reaction
- Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s)
Experiment results
About this model
The reading is the positive standard cell potential, E°cathode − E°anode. Moving an electrode to the other beaker keeps that value. A voltmeter with fixed leads would change sign when the leads are reversed.
The five reduction potentials reproduce AACT’s 2021 Voltaic Cells data, including magnesium at −2.38 V. The model assumes standard conditions; it does not vary concentration, temperature or current. Electrode changes show the direction of the reaction, without a physical time scale.
Guided investigations and notebook
Which metal gives up its electrons?
Put zinc in one beaker and copper in the other, join them, and close the switch.
Predict
Run it
Build a voltaic cell
Choose two half-cells. Follow the electrons and inspect each electrode.
Standard cell potential0.00 V
CircuitOpen
- Anode: oxidation
- Zn(s) → Zn²⁺(aq) + 2e⁻
- Cathode: reduction
- Cu²⁺(aq) + 2e⁻ → Cu(s)
- Balanced cell reaction
- Zn(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu(s)
Experiment results
About this model
The reading is the positive standard cell potential, E°cathode − E°anode. Moving an electrode to the other beaker keeps that value. A voltmeter with fixed leads would change sign when the leads are reversed.
The five reduction potentials reproduce AACT’s 2021 Voltaic Cells data, including magnesium at −2.38 V. The model assumes standard conditions; it does not vary concentration, temperature or current. Electrode changes show the direction of the reaction, without a physical time scale.
What the bench showed
Say what you found
Check
Which pair makes the most voltage?
Try different pairs of the five half-cells and compare what the meter reads.
Predict
Run it
Build a voltaic cell
Choose two half-cells. Follow the electrons and inspect each electrode.
Standard cell potential0.00 V
CircuitOpen
- Anode: oxidation
- Zn(s) → Zn²⁺(aq) + 2e⁻
- Cathode: reduction
- Ag⁺(aq) + e⁻ → Ag(s)
- Balanced cell reaction
- Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s)
Experiment results
About this model
The reading is the positive standard cell potential, E°cathode − E°anode. Moving an electrode to the other beaker keeps that value. A voltmeter with fixed leads would change sign when the leads are reversed.
The five reduction potentials reproduce AACT’s 2021 Voltaic Cells data, including magnesium at −2.38 V. The model assumes standard conditions; it does not vary concentration, temperature or current. Electrode changes show the direction of the reaction, without a physical time scale.
What the bench showed
Say what you found
Check
What this topic builds
- Pick the anode and the cathodeNot started
- Say which way electrons and ions moveNot started
- Calculate a cell’s voltageNot started