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Chemistry LibreTexts

10: Electrochemistry

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  • Elon Musk, an innovator in the field of harnessing renewable sources to generate electric power see a huge potential for electric cars to change the way Americans drive.

    • Selling an electric sports car creates an opportunity to fundamentally change the way America drives.- Elon Musk
    • I've actually made a prediction that within 30 years a majority of new cars made in the United States will be electric. And I don't mean hybrid, I mean fully electric.- Elon Musk

    Given the importance of energy production (and in particular, production from renewable sources) alluded to by Richard Smalley in his address to the United States Congress (see Chapter 1), Elon Musk’s vision seems well-aligned with Smalley’s priority. The generation and consumption of electrical energy and how it is harnessed to do work in the universe lends itself very nicely to discussion within the framework of thermodynamics. In this chapter, we will use some of the tills we have developed to relate electrochemical processes to thermodynamic variables, and to frame discussions of a few important topics.

    • 10.1: Electricity
      In 1799, Alessandro Volta showed that electricity could be generated by stacking copper and zinc disks submerged in sulfuric acid. The reactions that Volta produced in his voltaic pile included both oxidation and reduction processes that could be considered as half-reactions. The half-reactions can be classified as oxidation (the loss of electrons) which happens at the anode and reduction (the gain of electrons) which occurs at the cathode.
    • 10.2: The connection to ΔG
      A criterion for spontaneity, \(\Delta G\) also indicated the maximum amount of non p-V work a system could produce at constant temperature and pressure. And since we is non p-V work, it seems like a natural fit to extend this discussion to electrochemistry.
    • 10.3: Half Cells and Standard Reduction Potentials
      Much like G itself, E can only be measured as a difference, so a convention is used to set a zero to the scale. Toward this end, convention sets the reduction potential of the standard hydrogen electrode (SHE) to 0.00 V.
    • 10.4: Entropy of Electrochemical Cells
      The Gibbs function is related to entropy through its temperature dependence and a similar relationship can be derived for the temperature variance of E.
    • 10.5: Concentration Cells
      The generation of an electrostatic potential difference is dependent on the creation of a difference in chemical potential between two half-cells. One important manner in which this can be created is by creating a concentration difference. Using the Nernst equation, the potential difference for a concentration cell (one in which both half-cells involve the same half-reaction) can be expressed
    • 10.E: Electrochemistry (Exercises)
      Summary for Chapter 10 "Electrochemistry" in Fleming's Physical Chemistry Textmap.
    • 10.S: Electrochemistry (Summary)
      Exercises for Chapter 10 "Electrochemistry" in Fleming's Physical Chemistry Textmap.

    Contributors and Attributions

    • Patrick E. Fleming (Department of Chemistry and Biochemistry; California State University, East Bay)