This research encompasses many aspects of chemical education research including curriculum and pedagogical changes to the freshman and sophomore courses. Curriculum changes included the addition of recitations to the general chemistry and organic chemistry lectures and the creation of four new classes, CHEM 1001, 1002, 3091, and 3092. The addition of recitations was not limited to but was focused on improving DFW rates for these courses. CHEM 3091 and 3092 are chemistry internship and undergraduate teaching assistant classes. These courses were necessary to offer outside internship opportunities and training for undergraduate teaching assistants, respectively. CHEM 1001 and 1002 are chemistry classes for nonscience majors. These courses were created to attempt to increase the number of nonscience major students choosing chemistry to complete their science requirement. CHEM 1001 and 1002 were courses not offered at any other university and required that the course materials and textbooks for these classes to be created from scratch without any foundation from other courses. An unforeseen consequence of the creation of these courses was the need to improve scientific communication between scientists and non-scientists and even scientist and scientist. Pedagogical work included a video intensive lecture style (VILS) for disseminating the material in the newly created CHEM 1001 and 1002 courses. For general chemistry and organic chemistry lecture, the major change was the addition of required recitation sessions for these courses. Further pedagogical changes to the organic lecture included introduction of video lectures, implementation of active learning in the lecture and graded, online homework.

A growing body of evidence suggests that some Science teachers use drama-based strategies in order to promote understanding of abstract scientific concepts. These strategies employ action and imagination to simulate systems and processes that are too fast, too slow, too big, too small, too expensive or too dangerous to observe in the classroom. A small group of quantitative and qualitative studies over the past thirty years has suggested that these physical simulations enable learning in secondary students, by promoting discourse and by conveying concept features through a range of sensations. The field is as yet under-theorised, consisting of single case designs and unreplicated methodologies. This multiple case study focused upon an intervention design based on a pedagogical model developed in my Masters research. This study aimed to explore the characteristics of students' interaction and the nature of their resultant conceptions over four months. Each case focussed upon one of eight Key Stage 3 and Key Stage 4 classes across a variety of UK schools. In each, a curriculum-based particle theory topic was taught in a double-period lesson. Data included video, participant observations, and interviews with three students from each class collected at pre, post and delayed intervals. Findings suggested that the pedagogy engendered engagement and self-regulation in group model-making tasks, and supported thought experiment-type visualisations of dynamic processes. Conceptual development was found to continue up to four months after the lessons. A model of learning was developed in which social interaction and multimodal discourse promoted the association of conceptual features with affective, visual and embodied images, which supported recall, discussion and further conceptual development in the longer term.

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Os mapas conceituais (MCs) são organizadores gráficos com grande potencial para estimular a aprendizagem significativa. Porém, poucos trabalhos exploram o uso dos MCs elaborados pelo professor como material instrucional de Química. Nesta tese, a explicação química para dois fenômenos macroscópicos (cor nos fogos de artifício e a condução elétrica em diferentes materiais) foram escolhidos para serem representados e ensinados por meio dos MCs. A possibilidade de ler o MC de várias formas, a necessidade em estabelecer uma sequência de leitura e, a dificuldade do conteúdo representado podem gerar, no aluno que interage com o material, uma sensação de desorientação. A desorientação compromete os recursos cognitivos destinados à aprendizagem (processamento generativo) devido a uma alta complexidade do conteúdo (i.e., carga cognitiva intrínseca) ou a um formato de instrução inadequado (i.e., carga cognitiva extrínseca). Considerando os pressupostos da Teoria da Carga Cognitiva e da Teoria da Aprendizagem Multimídia, esses materiais devem ser elaborados de modo que as demandas cognitivas impostas ao aluno não excedam a limitada capacidade da MT, caso contrário, não sobrará recursos cognitivos suficientes para processar e adquirir novas informações, isto é, aprender. Sendo assim, o objetivo dessa tese foi avaliar o impacto de algumas estratégias para minimizar a desorientação provocada por MCs que organizam conteúdos de Química e, consequentemente, potencializar a aprendizagem de conceitos científicos. Três estudos foram conduzidos para avaliar o impacto do uso de dicas gráficas de navegação (Estudo I), do tipo de organização conceitual (Estudo II), do uso de recursos digitais associados ao MC (i.e., um hipertexto) e do nível de conhecimento prévio dos alunos (Estudo III) no ganho de conhecimento factual e conceitual e na carga cognitiva (e.g., esforço mental) declarada para compreender o conteúdo químico. Ao total, 253 alunos ingressantes à Escola de Artes, Ciências e Humanidades da Universidade de São Paulo participaram desta pesquisa entre os anos de 2014 e 2017. A metodologia quantitativa (em um planejamento quase-experimental) foi adotada para comparar estatisticamente as médias de desempenho e esforço mental dos alunos alocados em diferentes condições experimentais. Com base nos resultados, foi possível concluir que (1) independentemente do tipo de MC utilizado como material instrucional, todos os alunos foram capazes de aumentar o seu nível de conhecimento factual sobre o conteúdo químico e, (2) o uso da cor e da hierarquia conceitual como dicas gráficas de navegação foram capazes de minimizar a desorientação provocada pelos MCs via gestão de carga intrínseca e redução da carga extrínseca, respectivamente. O processamento generativo pôde ser potencializado pelo uso de recursos digitais associados ao MC, tornando-o um hipertexto com certo grau de orientação de navegação. Algumas implicações educacionais, limitações da pesquisa e possibilidade de estudos futuros também são apresentadas. / Concept maps (Cmaps) are graphical organisers with great potential to foster meaningful learning. However, just a few studies explore the use of teacher-prepared Cmaps as chemistry instructional material. In this thesis, chemical explanations for two macroscopic phenomena (the colour in fireworks and electric conductivity) are chosen to be represented and taught through Cmaps. The possibility of reading the Cmap in different ways, the need for establishing a reading sequence and the content difficulty can lead, for the learner who is interacting with the material, a sense of disorientation. Disorientation impairs the cognitive resources that should be used for learning (generative processes) due to either a high content complexity (i.e., intrinsic load) or an unsuited format of instruction (i.e., extraneous load). Based on the assumptions of Cognitive Load Theory and Multimedia Learning Theory, these materials should be elaborated in a way that the cognitive load imposed to the learners does not exceed the limited working memory capacity, otherwise, there are no left cognitive resources to process and acquire new knowledge (i.e., learn). The thesis\' goal was to evaluate the impact of some strategies in minimizing the disorientation of Cmap that organizes chemistry contents and, consequently, to foster scientific conceptual learning. Three studies were conducted to evaluate the impact of: using navigational graphical cues (Study I), different types of conceptual organisation (Study II), using digital resources linked to the Cmap (i.e., hypertext) and the level of learners\' prior knowledge (Study III) on the gain of factual and conceptual knowledge and the cognitive load (e.g., mental effort) related to understanding the chemical content. In total, 253 freshman university students to the School of Arts, Science and Humanities of the University of São Paulo participated in this research between 2014 and 2017. A quantitative methodology (by a pre-test-to-post-test quasi-experimental design) were adopted for statistically comparing the mean of performance and mental effort from students in different experimental conditions. Considering the results, it was concluded that: (1) regardless the type of Cmap used as instructional material, all students were capable to improve their level of factual knowledge about chemical concepts and (2) the use of colour and conceptual hierarchy as navigational graphical cues decreased Cmap disorientation by managing intrinsic load and reducing extraneous load, respectively. Generative processing was fostered using digital resources linked to the Cmap by offering a scaffold for hypertext navigation. Some educational implications, research limitations and future studies are also presented.

O presente trabalho recorre à Filosofia da Química como viés para investigar o processo de ensino-aprendizagem em duas disciplinas de Química Geral em um curso para formação de químicos. A investigação se baseou em diversas fontes: respostas dos estudantes via questionários, gravações de aulas, atividade dos estudantes em aula, resposta esperada pelo professor para essa atividade e entrevistas com professores das disciplinas, a fim de possibilitar a triangulação dos resultados. Procurou-se caracterizar a preferência dos estudantes e professores acerca dos tipos de teorias e evidências utilizadas em suas explicações. As teorias hipotéticas e as evidências experimentais mediadas por instrumentos analíticos, como o espectrofotômetro, foram preferidas pelos professores, mas os estudantes mostraram dificuldades em lidar com elas neste momento inicial de sua formação superior. Foi percebida, também, uma tensão subjacente entre a química das moléculas e a química das substâncias, cuja relação está internalizada pelos professores mas não pelos alunos, e que se reflete em suas escolhas pelos tipos de explicações. Essa tensão pode ser entendida a partir da relação entre fazer química (baseado fortemente em instrumentos para separação e caracterização de compostos, e nas teorias que descrevem a química das moléculas) e ensinar química em uma disciplina introdutória (como escolher conteúdos e abordagens que permitam entender a relação entre o nível fenomenológico macroscópico e os modelos explicativos submicroscópicos). Para o químico em formação, observar uma evidência experimental e relacioná-la com uma teoria que envolve entidades submicroscópicas para formar uma explicação é um processo muito complexo. Esse processo fica ainda mais complexo quando a evidência a ser utilizada é mediada por um instrumento. Assim, os resultados obtidos e apresentados nesta tese apontam para a questão de que a diferença entre os tipos de evidências experimentais (mediadas e não mediadas) não pode ser tratada como um conhecimento tácito no ensino superior de Química Geral. / This thesis takes the philosophy of chemistry as a guide to investigate the process of teaching and learning in two general chemistry disciplines in a training course for chemists. In order to enable triangulation of results, the study relied on several sources: students\' responses to questionnaires, recording of classes, classroom students\' activities, expected responses by the lecturer for activities, and interviews with the lecturers. The investigation sought to characterize the preferences of students and lecturers about the kinds of theories and evidences used in their explanations. Lecturers preferred hypothetical theories and experimental evidences mediated by analytical instruments such as the spectrophotometer. However, students showed difficulties in dealing with such theories and mediated evidences in this initial stage of their education. A subjacent tension between the chemistry of molecules and the chemistry of substances, whose relation is internalized by the lecturers but not by the students, was also reflected in their choices for the types of explanations. Such tension can be understood considering the relationship between making chemistry (which is strongly based on instruments for separation and characterization of compounds, and on theories which describe the behavior of molecules) and teaching chemistry on an introductory course (which requires the choosing of contents and approaches to describe the relationship between the macroscopic phenomenological level and the submicroscopic explanatory models). For a chemistry undergraduate, observing an experimental evidence and relating it to a theory which involves submicroscopic entities to form an explanation is a very complex process. This process becomes even more complex when the evidence to be used is mediated by instruments. Thus, the results obtained and presented in this thesis point to the issue that the difference between the types of experimental evidences (direct or mediated) cannot be treated as a tacit knowledge in a General Chemistry university course.

Este trabalho apresenta uma reflexão sobre o papel do princípio de Le Chatelier desde a sua criação e algumas implicações no ensino de química. Foram levantados aspectos históricos da evolução do princípio com o objetivo de discutir características como, por exemplo: o caráter universal do mesmo, problemas e limitações quanto à sua aplicação e possíveis alternativas ao uso do princípio. Também foram analisados como os livros didáticos de química no nível médio tratam muitos destes aspectos. Além disto, é realizada uma discussão nestes textos didáticos a respeito das variáveis que influenciam no estado de equilíbrio tais como: concentração, pressão, catalisador e temperatura. Um aspecto presente na análise destas variáveis foi o levantamento de ilustrações presentes nos livros baseando-se nos níveis de representação presentes no triângulo de Johnstone. Os principais resultados mostraram que os autores de livros de Química do Ensino Médio apresentam o conceito do princípio de Le Chatelier marcado por um caráter indutivo, vago, ambíguo, e sem apresentar uma fundamentação teórica e suas limitações, enfatizando-o como um princípio infalível ou uma verdade absoluta. Perpetuou-se no ensino de química, ao longo do tempo, a formulação mais simples e popular criada por Le Chatelier, no ano de 1888. Outra conclusão importante refere-se ao fato de a maioria das figuras presentes nos livros didáticos estar relacionada ao nível macroscópico e a concentração é a alteração mais discutida. Poucas são as figuras que interligam os três vértices do triângulo. Resta ao professor o desafio de incluir as ilustrações faltantes, principalmente as microscópicas pois estas têm o objetivo de explicar aos estudantes o que ocorre do ponto de vista molecular quando se altera o estado de equilíbrio químico. Portanto, este tratamento superficial do princípio pode favorecer processos de ensino-aprendizagem baseados na memorização, repetição e na sua utilização sem a compreensão exata dos fenômenos envolvidos. / This work presents a reflection on the role of the Le Chatelier\"s principle concerned by its creation and some implications in the teaching of chemistry. The main purpose was to analyze as high school chemical textbooks approach with this subject. For this, historical aspects of the evolution of the principle were studied with the objective of discussing important characteristics, for example: the universal character of the principle, his problems and limitations regarding their applications to previse changes in chemical equilibrium systems and the possible alternatives to the use of the principle. It was found that the principle formulations were similar to that more simple and popular wrote by Le Chatelier, in the year of 1888. It was also made an analysis of how the textbooks address the issue of variables that influence in the state of equilibrium such as: concentration, pressure, catalyst and temperature. Also was analyzed the illustrations present in these books with the objective of address the equilibrium change based in the of Johnstone\"s triangle (that explicitly shows the macroscopic, microscopic and representational levels of chemical knowledge). The main results showed that the majority of the figures in textbooks refers only to macroscopic level and the effects done by of the equilibrium reactants concentration change. There are few figures which are related the three levels represented in the Johnstone\"s triangle. Is very important that teachers include the illustrations missing, mainly the microscopic level, once that this level is essential to correct understand of chemical equilibrium change in the molecular level. In general, the authors of chemical textbooks present the Le Chatelier\"s principle in an inductive manner, vague and ambiguous. They never present theoretical aspects and limitations in the application of the principle. This stresses the infallible character of Le Chatelier\"s principle and transmits the idea that it is an absolute truth. This superficial treatment of the principle can encourage processes of teaching-learning based on memorization and the students can correctly use the principle in the problems solutions without have an exact understanding the phenomena.

Traditional chemistry laboratory courses have a manual consisting of “step-by-step” experiments; instructions are given to complete experiments, requiring minimal information/concepts processing to be successful. This experience leaves students unprepared for the real-world, where critical thinking skills are needed to conduct research. This study focused on building analytical techniques, conceptual knowledge, and critical thinking skills used to solve research problems. A new quantitative chemistry laboratory manual was developed to transition students from traditional to inquiry-based experiments, requiring analytical method development. Data showed students having less difficulty using the new manual (0.8281 average difficulty) on method development exam questions and experiments, compared to the traditional manual (0.600 average difficulty). T-test showed significant difference between item difficulty, p = 0.029. Using null hypotheses, the new laboratory manual led to an increase in students’ conceptual knowledge and research skills. They were able to use their knowledge and skills to successfully solve real-world related problems.

With the development and rapid spread of new teaching methods involving the use of Information and Communication technologies (ICT) the need of new researches has appeared. Cognitive skills (skills of achieving theoretical and practical knowledge) can be effectively developed through chemistry experiments when theoretical and practical knowledge are juxtaposed. The research topic of the dissertation is the impact of ICT based chemistry experiments on cognitive skills education during chemistry lessons. The research was conducted in one of city’s gymnasiums by construction of cognitive skills expression during chemistry lessons model and its’ implementation in education project. Summarized research results showed weaknesses of ICT implementation in chemistry teaching and limitations of virtual chemistry experiments application for cognitive skills education. The dissertation creates guidelines for other researches in the field of ICT implementation for natural science education. / Tobulėjant informacinėms ir komunikacinėms technologijoms (IKT) vis didesnį populiarumą ir plėtrą įgauna mokomosios kompiuterinės priemonės, todėl atsiranda būtinumas tirti šių mokymo priemonių įtaką ugdymui. Pažintinių mokėjimų (mokėjimų įgyti teorines ir praktines žinias) ugdymas efektyviai vyksta per chemijos pamokų demonstracinius ir laboratorinius eksperimentus, kai yra sugretinamos teorinės žinios su praktiniais mokėjimais. Disertacijoje nagrinėjama, kokią įtaką pažintinių mokėjimų ugdymui turi chemijos demonstraciniai bandymai ir laboratoriniai darbai atlikti IKT pagalba. Nagrinėjant disertacijoje keliamą mokslinę problemą sukurtas pažintinių mokėjimų raiškos chemijos pamokose modelis, parengtas ir vienoje iš miesto gimnazijų įgyvendintas ugdymo projektas. Apibendrinus atliktų tyrimų rezultatus, nustatyti IKT taikymo chemijos ugdyme trūkumai, aprašyti virtualių chemijos eksperimentų taikymo pažintinių mokėjimų ugdymui ribotumai. Disertacinis tyrimas sukuria gaires kitiems IKT taikymo gamtamoksliniame ugdyme moksliniams tyrimams.

Kinetic studies determining the second order rate constants for the monoepoxidation of cyclic dienes, 1,3-cyclohexadiene and 1,3-cyclooctadiene, and the epoxidation of cis-/trans-2-hexenes by dimethyldioxirane (DMDO) were carried out using UV methodology. Consistent with published results, the kinetics of cis-/trans-2-hexenes by DMDO showed greater reactivity of the cis-isomer compared to that of the trans-compound. Molecular modeling studies for the epoxidation of a series of cis-/trans-alkenes, by DMDO were carried out using the DFT approach. The mechanism of epoxidation by DMDO was modeled by determining the transition state geometry and calculating the electronic activation energies and relative reactivities. The calculations were consistent with a concerted, electrophilic, exothermic process with a spiro-transition state for all cases. Kinetic studies for the monoepoxidation of the cyclic dienes showed a greater reactivity for 1,3-cyclohexadiene compared to that for 1,3-cyclooctadiene. The DFT method was employed to successfully model the transition state for the monoepoxidation of the cyclic dienes by DMDO and successfully predict the relative reactivities. Student misconceptions, at the high school and/or middle school level involving energy changes and chemical reactions have been prevalently noted in literature (by ACS and AAAS). Two examples of these misconceptions are: 1) heat is always needed to initiate a chemical reaction and 2) all chemical reactions create or destroy energy. In order to address these types of misconceptions, an educational module detailing the influence of energy changes on chemical reactions has been developed in conjunction with the Bio-bus program for middle and high school students. Visual aids and hands-on activities were developed in the module to potentially help students overcome/deal with the common misconceptions. Surveys were designed to access the situations (determine the extent of the misconceptions) and the effectiveness of the educational module, before and immediately after the module and one-month later to determine retention. The educational module has been presented to approximately 100 high school students from underrepresented communities. Pre-survey data confirmed the presence of the common misconceptions reported in the literature. Data from the post-survey indicated the new instructional module enhanced the student’s interest of science and expanded their content knowledge and laboratory skills. The post-survey data (immediately following the module) showed a significant difference in two out of five misconceptions when compared to the pre-survey data. However, this significance decreased when the 1-month post-survey data were compared to the pre-survey data.