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Electrochemistry Dictionary - W
W: Symbol and abbreviation of watt.
Wh: Symbol and abbreviation of watt-hour.
Water electrolysis: Process for the
electrochemical decomposition of water in a divided electrolytic cell by electrolysis.
Typically, hydrogen gas is produced at the steel cathode (see hydrogen evolution)
and oxygen gas is produced at the nickel anode (see oxygen evolution). The cell
is divided to avoid mixing the hydrogen and oxygen gases. The electrolyte is
typically an aqueous potassium hydroxide solution. Potassium hydroxide is used
to provide a large ionic conductivity, even though the potassium is not reacting
at any of the electrodes (see supporting electrolyte).
Watt: Measurement unit of electrical
power. Symbol: "W". Related units are that of power density: watt/kilogram (W/kg)
and watt/liter (W/l).
Watt-hour: Measurement unit of electrical
energy. Symbol: "Wh". Related units are that of energy density: watt-hour/kilogram
(Wh/kg) and watt-hour/liter (Wh/l).
Wet cell: A cell in which
the liquid electrolyte is free-flowing.
Working electrode: The test or specimen
electrode in an electrochemical cell.
Or the electrode in a three-electrode cell where "the action is." The kinetics
and mechanism of the electrode reaction may be under investigation, or the reaction
occurring on the working electrode may be used to perform an electrochemical
analysis of the electrolyte solution. It can serve either as an anode or a cathode,
depending on the applied polarity. One of the electrodes in some "classical
two-electrode" cells can also be considered a "working" ("measuring," "indicator,"
or "sensing") electrode, e.g., in a potentiometric electroanalytical setup where
the potential of the measuring electrode (against a reference electrode) is
a measure of the concentration of a species in the solution.