Electrode Potentials and Electrochemical cells

• What is the key definition of oxidation in terms of electron transfer?

  Loss of electrons
• Reduction is defined as the gain of electrons
• In the half-equation Br2 + 2e → 2Br¯, bromine is being reduced.
• What is oxidation in terms of oxidation states?

  Increase in oxidation state
• Reduction is a decrease in oxidation state
• In the reaction of copper sulfate with zinc metal, copper is reduced and zinc is oxidized.
• What is the key definition of an oxidizing agent?

  Accepts electrons
• A reducing agent is a species that donates electrons
• An electrochemical cell converts the electron transfer in a redox reaction into electrical energy.
• What does each electrochemical cell consist of?

  Two half-cells
• The IUPAC convention for writing half-equations is to show the forward reaction as reduction.
• Steps to set up an electrochemical cell:

  1️⃣ Connect half-cells via external circuit

  2️⃣ Use a salt bridge to complete the circuit

  3️⃣ Measure the cell potential with a voltmeter
• What is the electromotive force (EMF) measured in an electrochemical cell called?

  Cell potential
• Standard conditions for an electrochemical cell include a gas pressure of 100 kPa
• The IUPAC convention places the positive electrode on the right-hand side of the cell diagram.
• At which electrode does oxidation occur in an electrochemical cell?

  Negative electrode
• Reduction occurs at the positive electrode in an electrochemical cell.
• Match the term with its definition:

  Standard electrode potential ↔️ Tendency to lose or gain electrons

  Primary standard ↔️ Standard hydrogen electrode

  Reference electrode ↔️ 0.00 V electrode potential

  Secondary standard ↔️ Measured against primary standard
• What is the standard electrode potential of the hydrogen electrode?

  0.00 V
• Standard electrode potential is measured by comparing a half-cell with a standard hydrogen half-cell.
• The polarity of a half-cell relative to hydrogen determines the sign of its electrode potential.
• Match the cell diagram notation with its meaning:

  Vertical solid line ↔️ Phase boundary

  Double vertical line ↔️ Salt bridge

  Highest oxidation state ↔️ Written next to salt bridge
• The cell potential is calculated using the equation E cell = Eº(RHS) - Eº(LHS).
• A platinum electrode is used in ion/ion half-cells because it is chemically inert
• What is the polarity of the platinum electrode in the chlorine half-cell?

  Positive
• What type of reaction do reactive metals undergo?

  Oxidation
• The most reactive metals have the most negative Eº values.
• Reactive non-metals undergo reduction
• The most reactive non-metals are good oxidizing agents.
• What is the cell potential in an electrochemical cell?

  Difference in Eº values
• According to IUPAC convention, which half-cell is placed on the right-hand side of a cell diagram?

  Positive electrode
• The cell potential is calculated using the equation E cell = Eº (RHS) - Eº (LHS).
• How is the standard electrode potential of a half-cell determined from the electrochemical series?

  By its position in the series
• In an electrochemical cell, chemical energy is converted into electrical energy.
• Electrons transfer current through the wire in an electrochemical cell.
• Ions transfer current through the solution in an electrochemical cell.
• Le Chatelier's Principle predicts how concentration changes affect Ecell.
• Predictions using electrode potentials indicate reaction rates.

  False
• What type of energy conversion occurs in an electrochemical cell?

  Chemical to electrical
• Non-rechargeable cells are also known as primary cells.