electrochemical cell

(noun)

A container containing an electrolyte and two electrodes; used to produce direct current electricity. One or more of them constitute a battery.

Related Terms

Examples of electrochemical cell in the following topics:

  • The Nernst Equation

    • In electrochemistry, the Nernst equation can be used to determine the reduction potential of an electrochemical cell.
    • In electrochemistry, the Nernst equation can be used, in conjunction with other information, to determine the reduction potential of a half-cell in an electrochemical cell.
    • It can also be used to determine the total voltage, or electromotive force, for a full electrochemical cell.
    • Find the cell potential of a galvanic cell based on the following reduction half-reactions where [Ni2+] = 0.030 M and [Pb2+] = 0.300 M.
    • The added half-reactions with the adjusted E0 cell are:

  • Concentration of Cells

    • Walther Nernst proposed a mathematical model to determine the effect of reactant concentration on the electrochemical cell potential.
    • The standard potential of an electrochemical cell requires standard conditions for all of the reactants.
    • The change in Gibbs free energy for an electrochemical cell can be related to the cell potential.
    • Under standard conditions, the output of this pair of half-cells is well known.
    • Discuss the implications of the Nernst equation on the electrochemical potential of a cell

  • Free Energy and Cell Potential

    • The basis for an electrochemical cell, such as the galvanic cell, is always a redox reaction that can be broken down into two half-reactions: oxidation occurs at the anode, where there is a loss of electrons, and reduction occurs at the cathode, where there is a gain of electrons.
    • This is the opposite of the cell potential, which is positive when electrons flow spontaneously through the electrochemical cell.
    • Calculate the change in Gibbs free energy of an electrochemical cell where the following redox reaction is taking place:
    • A demonstration electrochemical cell setup resembling the Daniell cell.
    • Calculate the change in Gibbs free energy of an electrochemical cell, and discuss its implications for whether a redox reaction will be spontaneous

  • Electrochemical Cell Notation

    • Cell notation is shorthand that expresses a certain reaction in an electrochemical cell.
    • Cell notations are a shorthand description of voltaic or galvanic (spontaneous) cells.
    • The anode half-cell is described first; the cathode half-cell follows.
    • A typical arrangement of half-cells linked to form a galvanic cell.
    • Produce the appropriate electrochemical cell notation for a given electrochemical reaction

  • Dry Cell Battery

    • In electricity, a battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy.
    • The dry cell is one of many general types of electrochemical cells.
    • Unlike a wet cell, a dry cell can operate in any orientation without spilling, as it contains no free liquid.
    • A common dry-cell battery is the zinc-carbon battery, which uses a cell that is sometimes called the Leclanché cell.
    • An illustration of a zinc-carbon dry cell.

  • Corrosion

    • Corrosion is commonly discussed in reference to metals, which corrode electrochemically.
    • In a corrosion system, the metal being corroded acts as the anode of a short-circuited electrochemical cell:

  • Voltaic Cells

    • An electrochemical cell is a device that produces an electric current from energy released by a spontaneous redox reaction.
    • This kind of cell includes the galvanic, or voltaic, cell, named after Luigi Galvani and Alessandro Volta.
    • Electrochemical cells have two conductive electrodes, called the anode and the cathode.
    • When an electrically conducting device connects the electrodes, the electrochemical reaction is:
    • The cell consists of two half-cells connected via a salt bridge or permeable membrane.

  • Equilibrium Constant and Cell Potential

    • If possible, a species will move from areas with higher electrochemical potential to areas with lower electrochemical potential.
    • In equilibrium, the electrochemical potential will be constant everywhere for each species.
    • It can also be used to determine the total voltage, or electromotive force, for a full electrochemical cell.
    • The cell equilibrium constant, K, can be derived from the Nernst equation:
    • Schematic of a galvanic cell for the reaction between Zn and Cu.

  • Mercury Battery

    • Mercury batteries were a common electrochemical battery that were phased out of mainstream use in the U.S. by the 1996 Battery Act.
    • A mercury battery, also called a mercuric oxide battery or a mercury cell, is a non-rechargeable electrochemical battery.
    • Mercury oxide cells are constructed with a zinc anode, a mercury oxide cathode, and potassium hydroxide or sodium hydroxide as the electrolyte.
    • A little extra mercuric oxide is put into the cell to prevent evolution of hydrogen gas at the end of its life.
    • Potassium hydroxide cells also have better performance at lower temperatures.

  • Predicting Spontaneous Direction of a Redox Reaction

    • In simple situations, an electrochemical series can be very useful for determining the direction of the reaction.
    • For example if we turn the zinc oxidation half-reaction around ($Zn^{2+} + 2e^- \rightarrow Zn \ E^o = -0.76 V$), the cell potential is reversed.
    • In order to predict if two reactants will take part in a spontaneous redox reaction, it is important to know how they rank in an electrochemical series.