Some analytical techniques, such as voltammetry, are relatively little used in undergraduate experimental disciplines in chemistry (and related sciences), although addressed in theoretical ones. Since, in contrast to what one thinks, voltammetric measurements are still often used in routine analysis, some of the most direct techniques will be highlighted in this text, with suggestions to [...]
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Initially the ideas of classical magnitude and classical body, continuous media, temporal and constitutive functions, density and rate will be shown, the latter being related to the rudimentary concepts of derivatives and functions. Then the concept of property is indicated, without the use of mathematical expressions, as well as the classification of properties into intensive, [...]
Here, some of the most typical concepts of thermodynamics, namely heat, internal energy, entropy and temperature are used for complementary understanding of the concepts of the enthalpy and energy of Helmholtz and Gibbs. The entropy concept has already been presented by this author, along with some of the concepts of temperature and the energies of [...]
Traditionally, the concept of entropy exists only for equilibria, which then require the same for the Helmholtz’s and Gibbs’ energies, because these are defined from it. As a result, all thermodynamics is restricted to equilibria, although it usually includes quantities classified as mechanical, such as volume and internal energy, which are considered outside the existing [...]
The amount of substance is one of the four fundamental properties of the thermodynamics in homogeneous media, along with volume, internal energy and entropy. This is a concept taught since high school, but it is not as elementary as it might seem. One aspect not always clear is the fact that it is related to [...]
This article presents the definitions of amount of substance, mole and concentration, in addition to the various units accepted by the International System for expressing concentration.
molar mass, mole, concentration, molarity, molality, SI
João Carlos de Andrade
Universidade Estadual de Campinas, Instituto de Química
João C. de Andrade
Carol H. Collins
Mathematics and Thermodynamics seem to be immiscible. Thermodynamicists take their own mathematical path which needs to return more than a century in time to meet the actual science done presently by mathematicians. Mathematicians are usually not interested in thermodynamics, and when they are, their work is not easily understood by thermodynamicists. Although both seem very [...]