Electrochemistry
Electrochemistry studies the relationship between electrical energy and chemical reactions. Master redox reactions, cell potentials, Nernst equation, and electrolysis calculations.
Key Concepts
Study Tips
- ✓Remember: OIL RIG - Oxidation Is Loss, Reduction Is Gain (of electrons)
- ✓Anode = oxidation, Cathode = reduction (alphabetical order helps)
- ✓E cell = E cathode - E anode (using standard reduction potentials)
- ✓Positive E cell means the reaction is spontaneous
Common Mistakes to Avoid
Students often confuse oxidation and reduction, forget to balance electrons in half-reactions, use the wrong sign for electrode potentials, or misidentify anode and cathode. Remember: in galvanic cells, anode is negative; in electrolytic cells, anode is positive.
Electrochemistry FAQs
Common questions about electrochemistry
1) Split into half-reactions, 2) Balance atoms other than O and H, 3) Add H2O to balance O, 4) Add H+ to balance H, 5) Add electrons to balance charge, 6) Multiply half-reactions to equalize electrons, 7) Add half-reactions and simplify.
The Nernst equation calculates cell potential under non-standard conditions: E = E standard - (RT/nF)ln(Q), or at 25C: E = E standard - (0.0592/n)log(Q). It shows how concentration affects cell voltage.
Use Faraday's laws: moles of electrons = current(A) x time(s) / 96485 C/mol. Then use stoichiometry to convert moles of electrons to moles of metal deposited, and multiply by molar mass.