Standard hydrogen electrode (SHE)

Definition

The standard hydrogen electrode (SHE) is a reference electrode with a defined potential of 0 volts under standard conditions. It consists of a platinum electrode in contact with 1 M H\textsuperscript{+} ions and hydrogen gas at 1 atm pressure.

5 Must Know Facts For Your Next Test

1. The SHE is used as the primary reference for measuring electrode potentials.
2. The potential of the SHE is defined as exactly 0 volts.
3. In practice, the SHE involves bubbling hydrogen gas over a platinum electrode immersed in an acidic solution.
4. Standard conditions for the SHE include a temperature of 25°C, H\textsubscript{2} gas at 1 atm, and a solution concentration of 1 M H\textsuperscript{+}.
5. The SHE serves as a baseline to determine the potentials of other electrodes by comparison.

Review Questions

Related terms

Electrode Potential:

The voltage developed by an individual half-cell or electrode, measured relative to a reference electrode.

Cell Potential:

The difference in potential between two half-cells in an electrochemical cell, also known as electromotive force (EMF).

Nernst Equation:

An equation that relates the reduction potential of a half-cell to its standard electrode potential, temperature, and activities (or concentrations) of chemical species involved.