All Flashcards
What are the steps to calculate standard cell potential (E°cell)?
- Identify the cathode and anode. 2. Find the standard reduction potentials for the cathode and anode. 3. Apply the formula: E°cell = E°cathode - E°anode.
Describe an alternative method to calculate E°cell?
- Reverse the oxidation half-reaction (change the sign of its potential). 2. Add the potentials of the reduction and oxidation half-reactions.
How do you calculate ΔG° from E°cell?
Use the formula: ΔG° = -nFE°cell, where n is the number of moles of electrons transferred and F is Faraday's constant.
How do you calculate the equilibrium constant K, from ΔG°?
Use the formula: where R is the ideal gas constant and T is the temperature in Kelvin.
What is the effect of a positive E°cell?
The reaction is spontaneous (thermodynamically favorable).
What is the effect of a negative E°cell?
The reaction is non-spontaneous (thermodynamically unfavorable).
What happens to ΔG° when E°cell is positive?
ΔG° becomes negative.
What happens to the equilibrium constant K, when ΔG° is negative?
The equilibrium constant K, becomes greater than 1, indicating that products are favored at equilibrium.
What is the effect of increasing the concentration of reactants on cell potential?
According to Le Chatelier's principle, increasing reactant concentration generally increases the cell potential (shifts the equilibrium towards product formation).
Define cell potential.
The driving force that pushes electrons through a circuit, measured in volts (V). Also known as electromotive force (EMF).
What is an anode?
The electrode where oxidation (loss of electrons) occurs.
What is a cathode?
The electrode where reduction (gain of electrons) occurs.
Define standard reduction potential.
The measure of the tendency of a chemical species to be reduced, expressed in volts relative to the standard hydrogen electrode (SHE).
Define Faraday's constant.
The amount of electric charge carried by one mole of electrons. Approximately 96,485 C/mol e-.
Define Gibbs Free Energy change (ΔG°).
A measure of the amount of energy available in a chemical or physical system to do useful work at a constant temperature and pressure.