Obtaining lead iodide in the laboratory : looking for answers

• Autor(a) principal: Ortigão, Manuela
• Data de Publicação: 2014
• Outros Autores: Paixão, Fátima
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.11/2724
• topic: Chemistry education; Current education; Chemical reactions; Experimental work

Everything we hear, see, smell, taste, and touch involves intricate series of chemical reactions and interactions in our body. Chemistry is not limited to beakers and laboratories. If is all around us, and the better we know chemistry, the better we know our world. Can we learn chemistry without experimental work? No. We cannot truly learn chemistry without experimental work. We can observe changes during chemical reactions including color changes, bubbling, "disappearance" of solid reactants, flame or formation of precipitates. Starting from the traditional reaction of precipitation of lead iodide, we present an articulated set of experimental activities guided by problem-questions aiming 10 develop the abilities of interpretation, handling and drawing conclusions, of the students of 8th grade (13-14 years o/d). To help students understanding precipitation reactions and also the very concept of chemical reaction, this concept is explored in three levels of analysis: macroscopic, submicroscopic, and symbolic These activities can be developed in the context of the classroom or explored, for example, in a non-formal educational context.