Developing and Implementing Inquiry-Based, Water Quality Laboratory Experiments for High School Students To Explore Real Environmental Issues Using Analytical Chemistry

This paper describes the rationale and the implementation of five laboratory experiments; four of them, intended for high-school students, are inquiry-based activities that explore the quality of water. The context of water provides students with an opportunity to study the importance of analytical methods and how they influence our everyday lives. It also provides an opportunity to expose students to scientific methods (e.g., inquiry) and behavioral responsibility that could influence their future lives as citizens. The inquiry-based activities consist of two parts. In the preliminary experiment, an analytical technique was introduced and the students learned analytical skills. On the basis of these, preliminary experiments, the students designed inquiry-based laboratory experiments involving relevant questions and decision making. Students explored parameters concerning water quality from different sources and had an opportunity to evaluate the data critically and to answer questions such as the following: Should we drink bottled water or tap water? How is the water quality monitored? What does water contain? The experiments involve qualitative and quantitative analyses of water salinity, water hardness, and the presence of organic compounds (volumetric versus spectrophotometric analysis of chloride in water), as well as determining water hardness by EDTA complexometric titration and water filtration.