Electrochemistry Notes for JEE
1. Electrochemical Cells
- Galvanic Cell (Voltaic Cell): Converts chemical energy into electrical energy.
Example: Daniel Cell (Zn | Zn2+ || Cu2+ | Cu)
- Anode (oxidation): Zn -> Zn2+ + 2e-
- Cathode (reduction): Cu2+ + 2e- -> Cu
- EMF of the cell: E0_cell = E0_cathode - E0_anode
- Electrolytic Cell: Uses electrical energy to drive non-spontaneous reactions.
Example: Electrolysis of water
2. Nernst Equation
- Used to calculate the EMF of a cell at non-standard conditions:
E = E0 - (0.0591/n) log [Products]/[Reactants]
3. Conductance and Kohlrausch's Law
- Specific Conductance (k): Conductivity of a solution.
- Molar Conductance (Lm): Conductivity per mole of electrolyte.
Lm = (1000 * k) / C
- Kohlrausch's Law: The limiting molar conductivity of an electrolyte is the sum of the individual ionic
contributions.
L0_m = l0_+ + l0_-
4. Faraday's Laws of Electrolysis
- First Law: Mass of a substance deposited is directly proportional to the charge passed.
m = ZQ = ZIt
1. Electrochemical Cells
- Galvanic Cell (Voltaic Cell): Converts chemical energy into electrical energy.
Example: Daniel Cell (Zn | Zn2+ || Cu2+ | Cu)
- Anode (oxidation): Zn -> Zn2+ + 2e-
- Cathode (reduction): Cu2+ + 2e- -> Cu
- EMF of the cell: E0_cell = E0_cathode - E0_anode
- Electrolytic Cell: Uses electrical energy to drive non-spontaneous reactions.
Example: Electrolysis of water
2. Nernst Equation
- Used to calculate the EMF of a cell at non-standard conditions:
E = E0 - (0.0591/n) log [Products]/[Reactants]
3. Conductance and Kohlrausch's Law
- Specific Conductance (k): Conductivity of a solution.
- Molar Conductance (Lm): Conductivity per mole of electrolyte.
Lm = (1000 * k) / C
- Kohlrausch's Law: The limiting molar conductivity of an electrolyte is the sum of the individual ionic
contributions.
L0_m = l0_+ + l0_-
4. Faraday's Laws of Electrolysis
- First Law: Mass of a substance deposited is directly proportional to the charge passed.
m = ZQ = ZIt
