14.2.1 Using Electrode Potentials

• What does electrode potential measure?

  Tendency to gain/lose electrons
• A positive electrode potential indicates a tendency to lose electrons.

  False
• Electrode potential is measured relative to the standard hydrogen electrode
• Match the features with their descriptions for the standard hydrogen electrode (SHE):

  Reference Potential ↔️ 0.00 V

  Components ↔️ Platinum electrode, 1 M $H^{ + }$, hydrogen gas
• What is the half-cell reaction for the SHE?

  $2H^{ + }(aq) +$$2e^{ - } \rightleftharpoons H_{2}(g)$
• The SHE operates under standard conditions of 298 K and 1 atm.
• Electrode potential represents the potential difference between a half-cell and the standard hydrogen electrode
• What is the electrode potential of the copper half-cell Cu^{2 + }(aq) + 2e^{ - } \rightleftharpoons Cu(s)</latex>?

  +0.34 V
• The standard hydrogen electrode (SHE) is assigned a standard electrode potential of 0.00 V.
• Steps to measure standard electrode potentials using the SHE:

  1️⃣ Prepare the half-cell with a 1 M solution of metal ions and an electrode of the same metal.

  2️⃣ Connect the half-cell to the SHE with a salt bridge.

  3️⃣ Attach a voltmeter to measure the potential difference.

  4️⃣ Record the voltmeter reading as the standard electrode potential.
• What is the standard electrode potential of zinc $Zn^{2 + }(aq) +$$2e^{ - } \rightleftharpoons Zn(s)$?


  -0.76 V
• The cell potential (E°cell) is calculated as the difference between the standard electrode potentials of the reduction and oxidation half-cells
• What is the formula for calculating cell potential (E°cell)?

  $E°_{cell} =$$E°_{reduction} - E°_{oxidation}$
• Match the half-cells with their standard electrode potentials:

  Copper ↔️ +0.34 V

  Zinc ↔️ -0.76 V
• The cell potential for a copper-zinc cell is +1.10 V under standard conditions.
• What is the standard electrode potential of copper ($Cu$)?


  +0.34 V
• Copper has a higher electrode potential than zinc, so it will be oxidized.

  False
• $E°_{cell}$ is calculated as the difference between the standard reduction and oxidation potentials, which in this case is +1.10 V
• What does the cell potential (E°cell) represent?

  Potential difference between half-cells
• E°_{cell} = E°_{reduction} - E°_{oxidation}</latex> is the correct formula for calculating cell potential.
• What is the standard electrode potential of zinc ($Zn$)?


  -0.76 V
• Electrode potential is measured relative to the standard hydrogen electrode, also known as SHE
• A negative electrode potential indicates a tendency to gain electrons.

  False
• What are the conditions for the standard hydrogen electrode (SHE)?

  298 K, 1 atm, 1 M $H^{ + }$
• The reference potential of the standard hydrogen electrode (SHE) is 0.00 V
• Steps to determine standard electrode potentials

  1️⃣ Prepare a half-cell with a 1 M solution of metal ions and an electrode of the same metal.

  2️⃣ Connect the half-cell to the SHE with a salt bridge.

  3️⃣ Attach a voltmeter to measure the potential difference.

  4️⃣ Record the voltmeter reading, which is the standard electrode potential (E°).
• The standard electrode potential of zinc is -0.76 V, indicating a higher tendency to lose electrons compared to hydrogen.
• What is the formula for calculating cell potential (E°cell)?

  $E°_{cell} =$$E°_{reduction} - E°_{oxidation}$
• The feasibility of a redox reaction is predicted using the value of $E°_{cell}$
• What does a positive $E°_{cell}$ indicate about the feasibility of a redox reaction?


  Spontaneous and feasible
• A negative $E°_{cell}$ suggests the reaction is non-spontaneous and requires energy input.
• Match the key concept with its description:

  Electrode Potential ↔️ Measures tendency of a half-cell to gain or lose electrons relative to SHE

  Standard Hydrogen Electrode (SHE) ↔️ Reference electrode with a potential of 0.00 V

  Cell Potential (E°cell) ↔️ Potential difference between reduction and oxidation half-cells

  Feasibility ↔️ Indicates whether a redox reaction is spontaneous or not