Electrochemistry Experiments — Harnessing Electron Flow
9 experiments
Electrochemistry experiments demonstrate the interconversion of chemical and electrical energy. Students build galvanic cells from different metals, measure cell voltages, perform electrolysis, and explore Faraday's laws. These experiments connect abstract thermodynamic concepts to tangible observations — lighting a bulb with a lemon battery or copper-plating a key.
Learning Objectives
Understand half-cell reactions, calculate standard cell potentials using electrode potential tables, verify Faraday's laws (mass deposited proportional to charge passed), and explore factors affecting cell voltage including concentration, temperature, and electrode surface area.
Key Techniques
Construct a Daniell cell using zinc and copper electrodes in their respective sulfate solutions connected by a salt bridge. Measure open-circuit voltage with a high-impedance voltmeter. For electrolysis, weigh electrodes before and after to verify Faraday's laws. Use a potentiostat for precise voltage control in advanced experiments.
Equipment Overview
Required: metal electrodes (Zn, Cu, Fe, Mg), electrolyte solutions, salt bridges (KNO3 in agar), voltmeter, ammeter, DC power supply for electrolysis, analytical balance (0.001 g). Advanced: potentiostat, reference electrodes (Ag/AgCl, SCE).
Activity Series Verification
Testing metal reactivity with displacement reactions
Verify the electrochemical activity series by testing whether metals can displace other metals from solution.
Concentration Cell
Generating voltage from concentration differences
Construct a concentration cell using copper half-cells at different concentrations and verify the Nernst equation prediction for cell potential.
Daniell Cell Construction
Building a classic zinc-copper galvanic cell
Construct a Daniell cell to measure the standard cell potential and observe the electrochemical reactions at each electrode.
Electrolysis of Copper Sulfate
Quantitative electrolysis with copper electrodes
Perform quantitative electrolysis of copper sulfate solution using copper electrodes and verify Faraday's first law of electrolysis.
Electrolysis of Water
Splitting water into hydrogen and oxygen gases
Decompose water into hydrogen and oxygen gases using electrolysis, and verify the 2:1 volume ratio predicted by stoichiometry.
Electroplating with Copper
Depositing a thin layer of copper onto a metal object
Electroplate a metal key or coin with copper, demonstrating the industrial process of electrodeposition and Faraday's laws.
Lemon Battery
Building a simple galvanic cell from citrus fruit
Construct a simple galvanic cell using a lemon, copper coin, and zinc nail to demonstrate how chemical energy converts to …
Rust Prevention Methods
Comparing galvanizing, oil coating, and sacrificial anodes
Compare different rust prevention methods and understand how galvanic protection (sacrificial anodes) works electrochemically.
Voltaic Cell Potential Measurement
Measuring EMF of various half-cell combinations
Measure the electromotive force (EMF) of multiple galvanic cell combinations and compare with standard reduction potential values.