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  • Potential and OHM’S

    Another important quantity in the study of electrochemical systems is the potential. We can define an electrostatic potential, ϕ, in terms of the work required to move a unit (positive) charge from infinity to a specific position in the metal or in solution. This work can also be thought of in terms of energy. The unit…

  • Current Density

    To this point in the chapter, we have considered the total current, I. However, as you know from your experience, some electrochemical devices are small like a hearing aid battery. Others are significantly larger, such as the battery used to start your car. You would not expect the total current from these devices to be similar.…

  • Faradaic Efficiency

    The electrochemical reactions that we have been discussing are called faradaic reactions since they involve electron transfer that is directly related to the consumption of reactants and the formation of products as described by Faraday’s law. To this point, we have only considered one reaction at each electrode. However, it is possible, and in fact common, for…

  • Faraday’s Law

    In this section, we examine Faraday’s law, which is the relationship between the amount of current that flows through the external circuit and the amount of material that is either consumed or produced in a half-cell reaction. To explore how this works, let’s return once again to the zinc reaction: (1.6) From the half-cell equation,…

  • Scientific Units, Constants, Conventions

    There are seven base units within the International System of Units (SI system), as shown in Table 1.1 for quick reference. Except for luminous intensity, all of the quantities are used extensively in this text. Among the base units is electric current, I, which is critical for the examination of electrochemical systems. Electric current is measured in amperes…

  • Importance of Electrochemical Systems

    Electrochemical systems are not only essential for our society but are also common in everyday life. Imagine a world without batteries to power your personal electronic devices. How would travel change without low-cost aluminum that is essential for aircraft? What if corrosion of the steel in bridges, the hulls of ships, superstructures of buildings, and…

  • Characteristics of Electrochemical Reactions

    Electrochemical reactions are reactions where electrons are transferred through a conductor from the species being oxidized to that being reduced. Most of the unique and important properties of electrochemical reactions are the result of the way that these electrons are transferred. These characteristics include the following: This textbook will help you to understand and to use…

  • Electrochemical Cells

    Electrochemical cells, such as the cell illustrated in Figure 1.1, lie at the heart of electrochemical systems. A typical electrochemical cell consists of two electrodes: an anode where oxidation occurs and a cathode where reduction takes place. Electrons move through an external circuit via an electronic conductor that connects the anode and cathode. The liquid solution that is between the…

  • Practice Problems

    P19.1. a. A gas-phase A+B system solvates A + B  AB with Ka = 0.5 at 298.15 K. Calculate the compressibility factor, apparent fugacity coefficients, and the true vapor phase mole fractions in a mixture at 298.15 K and 2 bar when the apparent concentration is yA = 0.45 using ideal chemical theory. b. A liquid-phase A+B system solvates A + B  AB with Ka = 0.7 at 298.15 K. Calculate the true…

  • Summary

    A simple way of remembering the qualitative conclusions of this analysis can be derived by considering the behavior of the fugacity coefficient. One can easily demonstrate that the fugacity coefficient of the monomeric species is insensitive to the extent of association if it is expressed on the basis of the true number of moles in…