We analyzed part of the pedagogical content knowledge (PCK) and its development in teachers and trainees of chemistry, and how the analysis of real teaching situations allows to innovate in the initial training teacher process. In order to gather data, in relation with the FONDECYT project (11130150), with a varied set of qualitative instruments we managed to create new instances of initial teaching training and collaboration with the school, achieving relevant changes in the way new teachers think and their knowledge in relation to the subject of teaching chemical dissolutions. (C) 2015 Published by Elsevier Ltd.