The comprehension of the reactivity of the elements is an important goal to be achieved in undergraduate courses in inorganic chemistry. Therefore, at Universidade Federal de São Carlos (UFSCar), the B.Sc. in chemistry has a laboratory course dedicated to the chemistry of the elements. However, we have noticed a decrease in students' interest in this discipline over the years. Hence, we decided to use inquiry-based methodology in a full semester of an experimental laboratory of "chemistry of the elements" in an attempt to increase their interest. As a guideline, we used the theme of water treatment to engage them in solving problems related to inorganic chemistry reactivity and noticed greater enthusiasm toward the curriculum and research methodologies. Furthermore, at the end of the course, both methodologies (traditional and inquiry-based) were evaluated by an anonymous questionnaire. By using a rating from 0 to 5 (ranging from worst to best), it was evident that the mean rate for the new methodology (4.2) was significantly higher than the rate given to the traditional methodology (2.3). The improvement in the overall performance of the report grades in comparison to the traditional methodology over the inquiry-guided one was complementary to the questionnaire, indicating that poor performance was diminished or even depleted. We believe that this methodology improved the students' level of confidence and knowledge, indicating that it could be applied to any other laboratory course.