OLIVEIRA, Bruno Peixoto de. Avaliação dos Livros Didáticos de Química e as Concepções de Alunos de Ensino Médio e Superior Sobre o Conteúdo dos Fenômenos Espontâneos. 2014. 78 f. Dissertação (Mestrado em química)- Universidade Federal do Ceará, Fortaleza-CE, 2014. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-05-31T19:09:46Z No. of bitstreams: 1 2014_dis_bpoliveira.pdf: 976772 bytes, checksum: d99871513fa45d8b1c8d8f2c7e661a66 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-31T23:20:11Z (GMT) No. of bitstreams: 1 2014_dis_bpoliveira.pdf: 976772 bytes, checksum: d99871513fa45d8b1c8d8f2c7e661a66 (MD5) / Made available in DSpace on 2016-05-31T23:20:11Z (GMT). No. of bitstreams: 1 2014_dis_bpoliveira.pdf: 976772 bytes, checksum: d99871513fa45d8b1c8d8f2c7e661a66 (MD5) Previous issue date: 2014 / Thermodynamics as an experimental branch of applied science and may become an important tool in the teaching and learning process, since, through this character can apply for the student to facilitate visualization of the concepts studied in class. This study aimed to analyze and evaluate the approach of content "Spontaneous Processes" in textbooks of Chemistry, currently recommended by the Ministry of Education through Textbooks Guide. An analysis of the textbooks currently recommended by the Ministry of Education with the goal of understanding how content "Spontaneous Processes" was held was approached and was in compliance with the guidelines contained in legal documents MEC. Through questionnaires with objective and subjective questions were presenting everyday phenomena analyzed the conceptions of students in regular and vocational high school on spontaneous phenomena, as well as newly admitted to the Bachelor's Degree in Chemistry from the cities of Fortaleza and Itapipoca students. Following the standards of the National Textbook Program of the five books currently recommended only one was deemed appropriate for the spontaneous processes, as this addresses entropy making their connection with the Second Law of Thermodynamics and through everyday examples. A differential with other books has been analyzed that this material also addresses another thermodynamic function that describes the spontaneous processes under conditions routinely found in most laboratories, i.e. constant temperature and pressure, which is the Gibbs energy. It was evident that students, through common sense, can quite easily describe a process as spontaneous or not. However, when asked which factor would determine whether a given phenomenon occurs spontaneously (Gibbs energy), misunderstandings and confusion are evident. This fact can be associated with the gap now left by the books indicated and used in schools investigated in this work. It is further proposed, using these results suggest that content in textbooks and an approach through the visualization and understanding of everyday phenomena as the MEC guidelines. / A Termodinâmica como um ramo experimental e aplicado da Ciência pode se tornar uma importante ferramenta no processo de ensino e aprendizagem, visto que, através deste caráter aplicado pode facilitar para o aluno a visualização dos conceitos estudados em sala de aula. Este trabalho se propôs a analisar e avaliar a abordagem do conteúdo “Processos Espontâneos” nos livros didáticos de Química, atualmente recomendados pelo Ministério da Educação através do Guia de Livros Didáticos. Foi realizada uma análise dos livros didáticos atualmente recomendados pelo Ministério da Educação com o objetivo de compreender como o conteúdo “Processos Espontâneos” era abordado e se estava em adequação com as orientações contidas em documentos legais do MEC. Através de questionários aplicados com questões objetivas e subjetivas apresentando fenômenos cotidianos foram analisadas as concepções de alunos do Ensino Médio regular e profissional sobre fenômenos espontâneos, bem como de alunos recém-admitidos no curso de Licenciatura em Química das cidades de Fortaleza e Itapipoca. Seguindo as normas do Programa Nacional do Livro Didático dos cinco livros atualmente recomendados, apenas um foi considerado adequado para os processos espontâneos, pois este aborda entropia fazendo sua ligação com a Segunda Lei da Termodinâmica e através de exemplos cotidianos. Um diferencial em relação aos outros livros analisados foi que este material, também aborda outra função termodinâmica que descreve os processos espontâneos em condições mais corriqueiramente encontradas em laboratórios, ou seja, em temperatura e pressão constante, que é a energia de Gibbs. Ficou evidenciado que os alunos, através do senso comum, conseguem com certa facilidade descrever um processo como espontâneo ou não. Entretanto, quando questionados sobre qual o fator que determinaria se um dado fenômeno ocorre espontaneamente (energia de Gibbs), são evidenciados equívocos e confusões. Este fato pode estar associado à lacuna deixada atualmente pelos livros indicados e utilizados nas escolas investigadas neste trabalho. Propõe-se ainda, através destes resultados, sugerir esse conteúdo nos livros didáticos e uma abordagem através da visualização e compreensão dos fenômenos cotidianos conforme orientações do MEC.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A TermodinÃmica como um ramo experimental e aplicado da CiÃncia pode se tornar uma importante ferramenta no processo de ensino e aprendizagem, visto que, atravÃs deste carÃter aplicado pode facilitar para o aluno a visualizaÃÃo dos conceitos estudados em sala de aula. Este trabalho se propÃs a analisar e avaliar a abordagem do conteÃdo âProcessos EspontÃneosâ nos livros didÃticos de QuÃmica, atualmente recomendados pelo MinistÃrio da EducaÃÃo atravÃs do Guia de Livros DidÃticos. Foi realizada uma anÃlise dos livros didÃticos atualmente recomendados pelo MinistÃrio da EducaÃÃo com o objetivo de compreender como o conteÃdo âProcessos EspontÃneosâ era abordado e se estava em adequaÃÃo com as orientaÃÃes contidas em documentos legais do MEC. AtravÃs de questionÃrios aplicados com questÃes objetivas e subjetivas apresentando fenÃmenos cotidianos foram analisadas as concepÃÃes de alunos do Ensino MÃdio regular e profissional sobre fenÃmenos espontÃneos, bem como de alunos recÃm-admitidos no curso de Licenciatura em QuÃmica das cidades de Fortaleza e Itapipoca. Seguindo as normas do Programa Nacional do Livro DidÃtico dos cinco livros atualmente recomendados, apenas um foi considerado adequado para os processos espontÃneos, pois este aborda entropia fazendo sua ligaÃÃo com a Segunda Lei da TermodinÃmica e atravÃs de exemplos cotidianos. Um diferencial em relaÃÃo aos outros livros analisados foi que este material, tambÃm aborda outra funÃÃo termodinÃmica que descreve os processos espontÃneos em condiÃÃes mais corriqueiramente encontradas em laboratÃrios, ou seja, em temperatura e pressÃo constante, que à a energia de Gibbs. Ficou evidenciado que os alunos, atravÃs do senso comum, conseguem com certa facilidade descrever um processo como espontÃneo ou nÃo. Entretanto, quando questionados sobre qual o fator que determinaria se um dado fenÃmeno ocorre espontaneamente (energia de Gibbs), sÃo evidenciados equÃvocos e confusÃes. Este fato pode estar associado à lacuna deixada atualmente pelos livros indicados e utilizados nas escolas investigadas neste trabalho. PropÃe-se ainda, atravÃs destes resultados, sugerir esse conteÃdo nos livros didÃticos e uma abordagem atravÃs da visualizaÃÃo e compreensÃo dos fenÃmenos cotidianos conforme orientaÃÃes do MEC. / Thermodynamics as an experimental branch of applied science and may become an important tool in the teaching and learning process, since, through this character can apply for the student to facilitate visualization of the concepts studied in class. This study aimed to analyze and evaluate the approach of content "Spontaneous Processes" in textbooks of Chemistry, currently recommended by the Ministry of Education through Textbooks Guide. An analysis of the textbooks currently recommended by the Ministry of Education with the goal of understanding how content "Spontaneous Processes" was held was approached and was in compliance with the guidelines contained in legal documents MEC. Through questionnaires with objective and subjective questions were presenting everyday phenomena analyzed the conceptions of students in regular and vocational high school on spontaneous phenomena, as well as newly admitted to the Bachelor's Degree in Chemistry from the cities of Fortaleza and Itapipoca students. Following the standards of the National Textbook Program of the five books currently recommended only one was deemed appropriate for the spontaneous processes, as this addresses entropy making their connection with the Second Law of Thermodynamics and through everyday examples. A differential with other books has been analyzed that this material also addresses another thermodynamic function that describes the spontaneous processes under conditions routinely found in most laboratories, i.e. constant temperature and pressure, which is the Gibbs energy. It was evident that students, through common sense, can quite easily describe a process as spontaneous or not. However, when asked which factor would determine whether a given phenomenon occurs spontaneously (Gibbs energy), misunderstandings and confusion are evident. This fact can be associated with the gap now left by the books indicated and used in schools investigated in this work. It is further proposed, using these results suggest that content in textbooks and an approach through the visualization and understanding of everyday phenomena as the MEC guidelines.

Orientador: Reginaldo Guirardello / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-20T02:10:55Z (GMT). No. of bitstreams: 1 YancyCaballero_DaisonManuel_M.pdf: 4027109 bytes, checksum: 0eb7d2d1826a2d09c663855c9ad4360c (MD5) Previous issue date: 2012 / Resumo: O presente trabalho tem como objetivo o estudo e aplicação da metodologia da minimização da energia de Gibbs no sistema para o cálculo do equilíbrio de fases, com e sem reação química, para o sistema reacional do biodiesel, utilizando técnicas de otimização global aliadas ao software GAMS, ferramenta computacional utilizada nesta pesquisa. Desse modo, diferentes algoritmos para o cálculo do equilíbrio químico e de fases foram desenvolvidos na forma de programação não-linear para testar diferentes casos de estudo; o primeiro caso envolve apenas a formação de possíveis fases líquidas, e são comparados alguns dados disponíveis na literatura de sistemas contendo os componentes presentes na formação do biodiesel com os resultados obtidos mediante a minimização da função de Gibbs; o segundo caso, equilíbrio de fases com reação química, envolve a formação de uma possível fase vapor e possíveis fases liquidas; dessa forma foi simulada a reação de transesterificação de óleos vegetais para produção de biodiesel, fazendo alguns testes em que são considerados pseudo-componentes e outros em que não. Desse modo foram utilizados os modelos termodinâmicos NRTL, UNIQUAC e UNIFAC para a representação das fases líquidas, com ajustes dos parâmetros de interação binária dos modelos NRTL e UNIQUAC mediante o principio de máxima-verossimilhança para os sistemas envolvidos; nesse caso também foi usado o GAMS. Os resultados obtidos demonstraram que o uso das técnicas de otimização global aliadas ao GAMS são ferramentas úteis e eficientes para calcular o equilíbrio químico e de fases mediante a minimização da energia de Gibbs, além de apresentar tempos computacionais razoavelmente pequenos. Além disso, para os casos que foram comparados com dados da literatura, observou-se uma boa concordância entre os dados simulados e experimentais / Abstract: In this work, the Gibbs energy minimization method was used in chemical and phase equilibrium calculations for system containing compounds in biodiesel production processes. So, global optimization techniques associated with the GAMS software were utilized. Thus, different algorithms to simultaneous calculations of chemical and phase equilibrium were developed in form of non-linear programming to test different case studies; in the first case, only the formation of liquid phases were considered, and the results obtained by direct minimizing of the Gibbs energy were compared with some data available in literature for the systems evaluated; in the second case, phase equilibrium with chemical reaction, were considered the formation of one vapor phase and several liquid phases. In such a way, the transesterification reaction of vegetable oils for biodiesel production was simulated, considering and no considering pseudo-components. In this way, different thermodynamic models were applied to represent the non-idealities of the liquid phases, such as, NRTL, UNIQUAC and UNIFAC models. Also, binary interaction parameters for NRTL and UNIQUAC models were adjusted using the maximum-likelihood method. Additionally, in adjustment process was used the GAMS software too. The results obtained showed that the use of global optimization techniques associated with the GAMS software are useful and efficient tools to calculate the chemical and phase equilibrium by minimizing of the Gibbs energy. Furthermore, the computational times spent in the calculations were quite small in all systems studied. Moreover, in the cases that were compared with literature data, a good agreement between predicted and experimental data was observed / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

The background to this bachelor thesis is an on-going project within the VINN Excellence Center Hero-m. The task in this thesis is to perform a literature survey about the martensite transformation and investigate how the resulting fraction depends on cooling below the Ms-temperature. Instead of calculating the undercooling for each of the known fractions of martensite the driving force will be evaluated. Several efforts have been made through the years to describe the relationships between fraction transformed austenite and temperature. The approaches to the first models were empirical and derived from collections of data regarding the amount of retained austenite at different quenching temperatures. Lately, studies have been made to derive a thermodynamical relationship using how the Gibbs energy is affected by increments in volume transformed austenite. Two equations are derived by calculating the resulting driving force at different known quenching temperatures and the respective percentage transformed martensite found in previous works. The data for the steels used show a characteristic slope when linearised. A trend for the steels which have a high characteristic slope is that they also have a high Ms temperature, and the steels which have a low characteristic slope tend to have a low Ms. Previous relationships which describe the martensitic transformation have considered the importance of the Ms temperature only in it being a starting temperature for the transformation. To further incorporate the Ms temperature in the equations presented, further research of the martensitic transformation is required. The approach in this thesis of using thermodynamically calculated data is a base for further investigation of the range of the martensite transformation.

Orientadores: Maria Alvina Krahenbuhl, Antonio Jose de Almeida Meirelles / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-13T05:54:13Z (GMT). No. of bitstreams: 1 Falleiro_RafaelMauricioMatricarde_M.pdf: 2025398 bytes, checksum: 267d9b60efd1dc4f0a2818661c23761d (MD5) Previous issue date: 2009 / Resumo: Esse trabalho irá contribuir com alguns dados inéditos de equilíbrio líquido-vapor de compostos que constituem o biodiesel, pelo interesse imediato que este último tem despertado no mundo. Dados de Equilíbrio Líquido-Vapor (ELV) para três misturas binárias de ácidos graxos saturados foram medidos com sucesso através da Calorimetria Diferencial Exploratória (DSC). Esses dados são de grande interesse para as indústrias, principalmente as de biodiesel, já que processos como a cristalização ou a separação indesejada de componentes pode ser minimizada a partir do levantamento desses dados. Contudo, mudanças na célula de pressão do calorímetro e o uso de panelas herméticas com furo na tampa (f = 250 µm) foram necessárias para que a técnica analítica fosse possível de ser aplicada, apresentando precisão nos resultados, uso de pouca quantidade de amostra e menor tempo de operação. Foram determinados experimentalmente a 50 mmHg dados ELV dos seguintes sistemas: ácido mirístico (C14:0) + ácido palmítico (C16:0), ácido mirístico (C14:0) + ácido esteárico (C18:0), ácido palmítico (C16:0) + ácido esteárico (C18:0). Na pressão de 8 mmHg investigou-se o sistema ácido linoléico (C18:2) + ácido oléico (C18:1). Para estes quatro sistemas foram preparadas pequenas quantidades de amostras (2,5 a 4,5 mg) em diferentes composições cuja fração molar do componente mais volátil variara de 0 a 1,0 em intervalos de 0,1. Os coeficientes de fugacidade para os componentes da fase vapor foram calculados usando o método de Hayden e O'Connell (Fredenslund et al., 1977) e o coeficiente de atividade para a fase líquida foi correlacionado pelos modelos tradicionais de gE : NRTL (Renon and Prausnitz, 1968), UNIQUAC (Abrams and Prausnitz, 1975) e Wilson (Prausnitz et al., 1999). Os ajustes dos parâmetros foram então comparados afim de determinar quais dos ajustes representava melhor o ELV. A modelagem termodinâmica é importante para o desenvolvimento de equipamentos para a produção de biodiesel e fundamentais nos processos de purificação. / Abstract:This work will contribute to some unpublished data of phase equilibria of compounds that form the biodiesel, which arouses the interest immediately. Vapor-liquid equilibrium (VLE) data for three binary mixtures of saturated fatty acids have been successfully measured through differential scanning calorimetry (DSC). These data are of great interest to the industries mainly of biodiesel, since processes such as crystallization or separation of undesired components can be minimized from such data. However, changes in the calorimeter pressure cell and the use of hermetic pans with caps with holes (f = 250 µm) have been necessary so that this analytical technique was possible to be applied, showing accuracy in results, shorter sample quantity and operational time. The systems studied at 50 mmHg in this work were: myristic acid (C14:0) + palmitic acid (C16:0), myristic acid (C14:0) + stearic acid (C18:0) e palmitic acid (C16:0) + stearic acid (C18:0). The linoleic acid (C18:2) + oleic acid (C18:1) binary mixture was investigated in the pressure of 8 mmHg. The binary systems were prepared using small quantities (2.5 to 4.5 mg) of samples in different mole fractions varying between 0.0 and 1.0 in relation to the most volatile component of each diagram. The fugacity coefficients for the components in the vapor phase have been calculated using the Hayden and O'Connell's method (Fredenslund et al., 1977) and the activity coefficients for the liquid phase have been correlated to the traditional gE models: NRTL (Renon and Prausnitz, 1968), UNIQUAC (Abrams and Prausnitz, 1975) and Wilson (Prausnitz et al., 1999). The set of parameters were then compared in order to determine which adjustments would best represent the VLE. The thermodynamic modeling is important for the development of equipment for the biodiesel production and purification. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

For many decades zirconium alloys have been commonly used in the nuclear power industry as fuel cladding material. Besides their good corrosion resistance and acceptable mechanical properties the main reason for using these alloys is the low neutron absorption. Zirconium alloys are exposed to a very severe environment during the nuclear fission process and there is a demand for better design of this material. To meet this requirement a thermodynamic database is useful to support material designers. In this thesis some aspects of the development of a thermodynamic database for zirconium alloys are presented. A thermodynamic database represents an important facility in applying thermodynamic equilibrium calculations for a given material providing: 1) relevant information about the thermodynamic properties of the alloys e.g. amount and composition of phases, oxygen activity, heat capacity etc, and 2) significant information for the manufacturing process e.g. heat treatment temperature. The basic information in the database is first the unary data, i.e. pure elements; those are taken from the compilation of the Scientific Group Thermodata Europe (SGTE) and then the binary and ternary systems. All phases present in those binary and ternary systems are described by means of the Gibbs energy as a function of composition and temperature. Many of those binary systems have been taken from published or unpublished works and others have been assessed in the present work. The elements included in the databse are: C, Fe, Cr, Nb, Ni, Mo, O, Si, Sn, and Zr + H, and the assessment performed under this thesis are: Cr-Sn, Mo-Zr, Sn-Zr, Fe-Nb-Zr and Nb-O-Zr. All the calculations have been made using Thermo-Calc software and the representation of the Gibbs energy obtained by applying Calphad technique with some use of ab initio calculations. / QC 20100902

Zeolite nucleation and growth is a complex problem that has been widely investigated but still not completely understood. However, a full understanding of this process is required in order to develop predictive models for the rational design and control of the zeolite properties. The primary objective of this dissertation is to determine the strength of organicinorganic interactions (i.e., the adsorption Gibbs energy) in transparent synthesis mixtures using PFG NMR spectroscopy, in order to provide more information for a better understanding of zeolite nucleation and growth. Three main tasks were conducted in this work. The first was an investigation of the organocation role in precursor mixtures of silicalite-1, where the Gibbs energy of the organocation adsorption on the silica particles was determined at 25 degrees C. The findings showed that small changes in the adsorption Gibbs energy resulting from the differences in the molecular structure of the organocations lead to large changes in both the stability of the precursor particles and the rate of silicalite-1 formation. The second was an in situ PFG NMR investigation of silicalite-1 synthesis mixtures, where the adsorption Gibbs energy was determined at 25 degrees C and 70 degrees C, and the time evolution of silicalite-1 was monitored at synthesis conditions. The findings showed similar adsorption Gibbs energies at 25 degrees C and 70 degrees C. Also, a maximum in the organocation diffusion coefficients was observed during the time evolution of silicalite-1, which was associated with the exothermicendothermic transition occurring during the synthesis. The third was a systematic investigation of silicalite-1 precursor mixtures with varying degrees of dilution, where the effect of the composition of the mixtures on their conductivity, pH and particle size distribution (PSD) was studied. The results showed that conductivity, pH, and PSD are strongly affected by the mixture composition. The main conclusion of this research is that the strength of the organic-inorganic interactions in transparent synthesis mixtures can be determined from experimental data of the organocation self-diffusion coefficients obtained with PFG NMR spectroscopy. The outcome information of this research should contribute to the development of a more detailed molecular-level description of the zeolite nucleation and growth, which is expected to allow the emergence of a new generation of materials by design.

La thèse est centrée sur la modélisation de la physique du comportement d’un alliage binaire et l’implémentation du meilleur modèle mathématique pour simuler le changement de phase liquide solide en tenant compte de la vitesse de refroidissement, la vitesse de solidification, la ségrégation, la convection naturelle et la surfusion afin d’optimiser la capacité de stockage de chaleur d'un tel matériau. Dans le présent travail, les températures pour lesquelles le changement de phase s'opère sont estimées grâce aux diagrammes des phases et la méthodologie CALPHAD qui retraduisent les différentes phases d'un alliage binaire, y compris la transformation isotherme. Pour cela, la minimisation de l'énergie de Gibbs est résolue dans un code de calcul développé à cette occasion et aboutit à l'identification des phases stables du matériau. Pour un intervalle de température souhaite le code permet d'estimer rapidement la décharge de chaleur pour la composition de l'alliage sélectionné en équilibre ou hors équilibre. Dans la méthode proposée, la vitesse de refroidissement du système permet de calculer la vitesse de solidification. Puis,celle-ci établit la relation entre la cinétique globale et la macrostructure. Basé sur le modèle de non-équilibre local, qui dépend de la variation du coefficient de partition, le degré de surfusion est prédit à partir de la vitesse de refroidissement appliquée. Une étude bibliographique a été réalisée pour amener une comparaison numérique et assurer la capacité de notre méthode à reproduire le changement de phase, en incluant des phénomènes spécifiques tels que la surfusion et la recalescence. / Latent Heat Thermal Energy Storage (LHTES) shows high storage density compared to sensible thermal systems. For high temperature applications, the use of alloys as phase change materials presents many advantages. Principally, varying alloy composition allows controlling the storage\discharge of thermal energy through an expected temperature range (defined by the heat source), and the high thermal conductivity givessuitable heat transfer properties to the system that receives/supplies the energy. However, some systems need a specific temperature range to correctly operate. In such conditions, subcooling (also known as undercooling) and segregation are undesirable phenomena in alloys when they are used as PCM. In thepresent work, we propose a method to predict the latent heat release during phase transformation of a binaryalloy submitted to a controlled cooling rate, including subcooling, segregation and variation of composition.This thesis describes the physical models that apply when heat is released from such a material. We takeinto consideration the cooling rate applied to the PCM, the solidification velocity, convective phenomena,melting temperature and subcooling. In the present work, phase diagrams and the CALPHAD methodologyare used to determine the temperature range for phase change (or constant temperature value for isothermal transformation) by minimizing the Gibbs equilibrium energy. The Gibbs free energy minimization has been implemented in a homemade numerical code. The material can be screened with different compositions for equilibrium or off-equilibrium solidification allowing quick selection of the optimal material for the specific heatsource. In the proposed method, the solidification velocity is obtained from the cooling rate. Then, variationin microstructure is driven by the solidification velocity using the local non-equilibrium diffusion model. Based on the local nonequilibrium model that depends on the partition coefficient variation, the subcooling degree, wich is derived from the applied cooling rate is predicted. A bibliographic study has been carried out and anumerical comparison has been undertaken to ensure the capacity of our code to reproduce the phase change of various materials that include phenomena such as subcooling and recalescence. The results highlight that the cooling rate is one of the most important parameters in the performance of the thermal storage, having a large effect on segregation and subcooling degree. Moreover, we show the influence ofpartition coefficient on the time evolution of solid fraction, considering a constant or a composition-dependent value. We can conclude that the latent heat release can be correctly predicted provided that the method correctly predicts the phase diagram and the variable partition coefficient. This work helps to accelerate the design and development of thermal storage systems and lays the foundation to continue exploring other kinds of materials (e.g. paraffins).

[pt] No presente trabalho foram realizadas medidas de capacidade térmica à pressão constante do espinélio Al2MnO4 na faixa entre 2 e 873 K. No intervalo entre 2 e 300 K empregou-se um calorímetro de relaxação térmica. Os dados evidenciaram a presença de uma anomalia em torno de 33 K, cuja componente magnética pôde ser constatada mediante medidas de capacidade calorífica com campo magnético constante, bem como também medidas de magnetização específica como função da temperatura. A contribuição entrópica associada à mencionada anomalia foi considerada no cálculo da entropia molar a 298.15 K do óxido em questão (116.05 mais ou menos 5.2 J/mol.K), valor este consistente com valores da literatura para outros espinélios. Na faixa entre 323 e 873 K empregou-se um calorímetro diferencial de varredura. Os dados foram ajustados quantitativamente com o modelo de Berman e Brown, incluindo-se no ajuste o valor de capacidade térmica a 298.15 K, obtido via calorimetria de relaxação térmica. Empregando-se o valor de entropia molar determinado no presente trabalho, os parâmetros do modelo de Berman e Brown estimados com os dados em temperaturas elevadas, e uma estimativa disponível na literatura para a entalpia de formação do óxido Al2MnO4, construiu-se um modelo para a dependência térmica da energia de Gibbs do referido composto válido na faixa entre 298.15 e 2114 K. O modelo foi testado com sucesso no acesso termodinâmico das propriedades do sistema Al2O3-MnO. / [en] In the present work the constant pressure molar heat capacity of the spinel Al2MnO4 was measured between 2 K and 873 K. In the interval between 2 K and 300 K a relaxation calorimeter was employed. The data indicated the presence of a thermal anomaly around 33 K, whose magnetic component could be evidenced through measurements of the heat capacity with a constant applied magnetic field, and also through specific magnetization data as a function of temperature. The entropic contribution of the thermal anomaly was considered in the calculation of the molar entropy of the oxide at 298.15 K (116.05 more or less 5.2 J/mol.K), and the calculated value has proven to be consistent with values published earlier for other spinel compounds. In the interval between 323 and 873 K a differential scanning calorimeter was employed. The data were quantitatively modeled with the function proposed by Berman and Brown, including the heat capacity value obtained at 298.15 K accessed through the relaxation calorimeter route. By using the molar entropy at 298.15 K, the values of the parameter estimated for the Berman and Brown model with the heat capacity data at elevated temperatures, and an estimative for the heat of formation of the spinel Al2MnO4 extracted from the literature, it was possible to construct a model for the thermal dependence of the Gibbs energy of this compound valid between 298.15 K and 2114 K. The model was successfully tested in the thermodynamic assessment of the properties of the system Al2O3-MnO.