Licenciatura em Química (Sede)

URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/26


Siglas das Coleções:

APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso

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    Reações oscilantes e a entropia
    (2019-07-29) Carneiro, Mikelâne de Oliveira; Soares Neto, Luciano de Azevedo; http://lattes.cnpq.br/7676222115726194; http://lattes.cnpq.br/5531450021947295
    This work has as main objective to describe the oscillating reaction and its relation with entropy according to the contribution of Prigogine. Oscillating reactions for a long time were not accepted, as it was thought to violate the second law of thermodynamics, entropy, because they occur in open systems and away from chemical equilibrium, as many scientists only recognized the term entropy in isolated systems. Reversible, this idea gained notoriety because the entropic term arose from the operation of Carnot's thermal machine. With the need to explain entropy in systems of nature, giving rise to the term "irreversibility", Boltzmann brings in his analysis the behavior of gas. In this way he treats entropy in a probabilistic manner, but Boltzmann does not take into account that gas can interact, resulting in an energy balance of the system, this is only possible through the free energy of Gibbs, thus causing if the reaction is or not spontaneous. In 1950 comes the first oscillating reaction accepted by the scientific community, called Belesouv-Zhabostinsky reaction. With the difficulty of understanding the entropy in these reactions and even creating a mechanism, Ilya Prigogine in her studies develops a theory that gave her full prestige, the dissipative structures, thus giving her the Nobel Prize for such prowess, as these dissipative structures allowed the analysis of entropy in these reactions. Through Prigogine's analysis of dissipative structures we reproduce two systems of oscillations, temporal and spatial from the Belesouv-Zhabostinsky reaction system. During the reaction we reproduce, these oscillations occur due to an energy balance between entropy and Gibbs free energy. According to Prigogine this happens because in a system, open and far from equilibrium, entropy is capable of evolving in order to restructure and reorganize, surviving by dissipating the energy of the system in the local process, so that the fall that gets in your internal entropy is "paid" for the entropic dissipation of your system. Thus entropy is a structuring theme for chemistry, generating a more accurate view of its meaning and its implications.