Electrode potentials and electrochemical cells (A-level only) key terms

Standard Hydrogen Electrode

A reference electrode based on the half-reaction of hydrogen ions gaining electrons to form hydrogen gas, used to measure electrode potentials.

Electrode Potential

The measure of the tendency of a chemical species to be reduced, expressed in volts, relative to the standard hydrogen electrode.

Standard Electrode Potential

The measure of the tendency of a chemical species to be reduced, measured under standard conditions.

Electrochemical Cell

A device that converts chemical energy into electrical energy through redox reactions.

Standard electrode potential

The measure of the individual potential of a reversible electrode at standard conditions, typically measured against the standard hydrogen electrode.

Cell potential

The voltage generated by an electrochemical cell, calculated from the standard electrode potentials of the half-cells involved.

electrochemical cell

A device that converts chemical energy into electrical energy through redox reactions.

standard electrode potential

The measure of the tendency of a chemical species to be reduced, measured under standard conditions.

Electromotive Force (EMF)

The voltage developed by any source of electrical energy, measured in volts (V).

Electrochemical Cell

A device that converts chemical energy into electrical energy through redox reactions.

Standard Electrode Potential

The measure of the tendency of a chemical species to be reduced, measured under standard conditions.

Electrochemical Cell

A device that converts chemical energy into electrical energy through redox reactions.

standard conditions

The specific conditions (usually 1 atm pressure and 298 K temperature) under which measurements are made to ensure consistency.

limitations of predictions

Factors that can affect the accuracy of predictions made based on standard conditions, such as concentration changes and temperature variations.

fuel cell

A device that converts chemical energy from a fuel into electrical energy through a chemical reaction, typically involving hydrogen and oxygen.

rechargeable cell

A type of electrochemical cell that can be recharged by applying an external electrical current, allowing it to be used multiple times.

cell potential

The voltage produced by an electrochemical cell, determined by the difference in standard electrode potentials of the two half-cells.

electrode potential

The measure of the tendency of a chemical species to be reduced, expressed in volts, relative to the standard hydrogen electrode.