Márcia Gorette Lima da Silva

Determinação do teor de cálcio em comprimido à base de lactato de cálcio utilizado no tratamento da osteoporose

The present study utilized thermogravimetry (TG) and optical emission spectrometry with inductively coupled plasma (ICP/OES) to determine the amount of calcium in calcium lactate tablets used in the treatment of osteoporosis. Thermogravimetry results indicated that the decomposition temperature of CaCO3 occurred at 603.9 and 609.4 oC in the samples of calcium lactate and tablets, respectively. The calcium content obtained by TG for the tablets sample showed a similar result to that disclosed by ICP-OES, indicating a value of 8.93% for both techniques.

Vivenciando a estratégia de Resolução de Problemas: dificuldades de futuros professores de química

Abstract This paper presents some results of a didactic and investigative intervention in the context of pre-service chemistry teachers at the Federal University of Rio Grande do Norte, Brazil. We sought to investigate the nature of the difficulties faced by future teachers in problem solving, and how they reflect on these difficulties in the perspective of building knowledge by a didactic strategy for problem solving based in their own experiences. For this purpose it was organized and implemented a sequence of activities that involve the problem solving strategy. The results suggest that experience of the strategy contributed to a reflective awareness of the students’ difficulties for learning and, of course their own difficulties in teaching and learning, as pre-service teachers.