ELECTROCHEMISTRY

Properties & Key Points:

• Anode: The electrode where oxidation occurs.
• Cathode: The electrode where reduction occurs.
• Anode: Connected to the positive terminal, oxidation occurs here.
• Cathode: Connected to the negative terminal, reduction occurs here.

• The difference in potential between the two electrodes of an electrochemical cell.

Properties & Key Points:

• The electrode potential of a half-cell under standard conditions (1 M concentration, 1 atm pressure, 25°C).
• Standard Hydrogen Electrode (SHE): Assigned an electrode potential of \( 0 \, \text{V} \).

Properties & Key Points:

• Relates cell potential to concentration of ions in non-standard conditions.
• \( E_{\text{cell}} \): Cell potential.
• \( E^\circ_{\text{cell}} \): Standard cell potential.
• \( R \): Gas constant (8.314 J/mol·K).
• \( T \): Temperature in Kelvin.
• \( n \): Number of moles of electrons transferred.
• \( F \): Faraday constant (96485 C/mol).
• \( Q \): Reaction quotient.

Properties & Key Points:

• Gibbs free energy change (\( \Delta G \)) and cell potential are related as follows:
• \( \Delta G \): Gibbs free energy change.
• \( n \): Number of moles of electrons.
• \( F \): Faraday constant.
• \( E_{\text{cell}} \): Cell potential.

Properties & Key Points:

• \( \kappa \): Conductivity.
• \( G \): Conductance.
• \( l \): Length of the conductor.
• \( A \): Cross-sectional area.
• \( \Lambda_m \): Molar conductivity.
• \( c \): Molar concentration of the solution.

Properties & Key Points:

• At infinite dilution, each ion contributes a specific part to the molar conductivity.
• \( \Lambda_m^\circ \): Molar conductivity at infinite dilution.
• \( \lambda^0_{\text{cation}} \): Contribution from the cation.
• \( \lambda^0_{\text{anion}} \): Contribution from the anion.

Properties & Key Points:

• \( m \): Mass of substance.
• \( Z \): Electrochemical equivalent.
• \( Q \): Quantity of electricity.
• \( m_1, m_2 \): Masses of different substances.
• \( E_1, E_2 \): Equivalent weights.

Properties & Key Points:

• A redox reaction where metals are gradually oxidized.
• Rusting of Iron: Iron reacts with oxygen and water to form rust.