electrochemical cells examples

📚 Quick Study Guide

🔍 Electrochemical cells (also known as voltaic or galvanic cells) convert chemical energy into electrical energy through spontaneous redox reactions.

⚡️ Key Components:
• Anode: The electrode where oxidation occurs (loss of electrons).
• Cathode: The electrode where reduction occurs (gain of electrons).
• Electrolyte: A solution containing ions that conduct electricity.
• Salt Bridge: A tube containing an electrolyte that connects the half-cells, allowing ion flow to maintain charge balance.

📝 Cell Notation (example: $Zn(s) | Zn^{2+}(aq) || Cu^{2+}(aq) | Cu(s)$):
• Single vertical line (|) represents a phase boundary.
• Double vertical line (||) represents the salt bridge.

➕ Calculating Cell Potential ($E_{cell}$):
• $E_{cell} = E_{cathode} - E_{anode}$ (using standard reduction potentials)
• Nernst Equation (under non-standard conditions): $E_{cell} = E^o_{cell} - \frac{RT}{nF}lnQ$ where R is the ideal gas constant, T is temperature, n is the number of moles of electrons transferred, F is Faraday's constant, and Q is the reaction quotient.

💡 Tips for Remembering:
• AN OX (Anode Oxidation) and RED CAT (Reduction Cathode)
• Electrons flow from Anode to Cathode.

🧪 Practice Quiz

1. Which of the following is the correct definition of oxidation?
   1. A) Gain of electrons
   2. B) Loss of electrons
   3. C) Gain of protons
   4. D) Loss of protons
2. In an electrochemical cell, where does reduction occur?
   1. A) Anode
   2. B) Cathode
   3. C) Salt Bridge
   4. D) Electrolyte
3. What is the purpose of the salt bridge in an electrochemical cell?
   1. A) To prevent the flow of electrons
   2. B) To allow the flow of electrons
   3. C) To maintain charge balance
   4. D) To increase the rate of reaction
4. Given the standard reduction potentials: $Cu^{2+} + 2e^- \rightarrow Cu$ ($E^o = +0.34V$) and $Zn^{2+} + 2e^- \rightarrow Zn$ ($E^o = -0.76V$), what is the $E_{cell}$ for the reaction $Zn(s) + Cu^{2+}(aq) \rightarrow Zn^{2+}(aq) + Cu(s)$?
   1. A) -0.42 V
   2. B) +1.10 V
   3. C) -1.10 V
   4. D) +0.42 V
5. Which component of an electrochemical cell contains ions that conduct electricity?
   1. A) Anode
   2. B) Cathode
   3. C) Electrolyte
   4. D) Salt Bridge
6. What does a single vertical line (|) represent in cell notation?
   1. A) Salt Bridge
   2. B) Phase Boundary
   3. C) Flow of Electrons
   4. D) Standard Conditions
7. What is the mnemonic used to remember where oxidation and reduction occur?
   1. A) RED CAT, AN LION
   2. B) AN OX, RED CAT
   3. C) CAT RED, OX AN
   4. D) OX AN, LION RED