The electrode defined as having a potential of zero under standard conditions. All redox potentials
are measured relative to the standard hydrogen electrode. The potentials are measured relative to
the standard hydrogen electrode at 25°C and with 1.0 M of each ion in solution.
Standard potential
The voltage associated with a half-reaction of a specific redox reaction. Generally tabulated as a
reduction potential, compared to the SHE.
Standard temperature and pressure (STP)
0°C (273 K) and 1 atm. Used for measuring gas volume and density.
State
The set of defined macroscopic properties of a system that must be specified in order to reproduce
the system exactly. Sometimes also used as a synonym for Phase.
State function
A function that depends on the state of a system but not on the path used to arrive at that state.
Strong acid
An acid that undergoes complete dissociation in an aqueous solution; e.g., HCl.
Strong base
A base that undergoes complete dissociation in an aqueous solution; e.g., KOH.
Sublimation
A change of phase from solid to gas without passing through the liquid phase.
Subshell