'How does pH affects soil quality?': the use of a problematizing experimental didactic to analyze the three pedagogical moments

Chemistry is considered a complex and uninteresting subject for most of the high school students. We consider that a way to transform the Chemistry into something interesting and understandable to students consists of using the problematizing experimentation combined to the Science, Technology and Society approach (STS), since these approaches can make teaching chemistry more contextualized and develop a criticism in students. This study aimed to elaborate and apply a problematizing experimental workshop, as well as to analyze the three pedagogical moments and their influence on the cognitive and critical development of the student from the question "How does pH affects soil quality?". A workshop was held within the content of acids, bases, pH and pH indicators and was attended by students from a pre-college preparation. From the analysis of the discussions carried out before and after each stage, it was notice that workshop contributed to the development of scientific knowledge and at the same time it allowed a critical reflection of reality. It is also noteworthy that the workshop promoted the first contact of students from a pre-college preparation with an experimental activity, perhaps constituting this fact, its main merit.