Development and Implementation of a Simple, Engaging Acid Rain Neutralization Experiment and Corresponding Animated Instructional Video for Introductory Chemistry Students

Here we describe an acid rain neutralization laboratory experiment and its corresponding instructional video. This experiment has been developed and implemented for use in the teaching laboratory of a large introductory chemistry course at Brown University. It provides a contextually relevant example to introduce beginner-level students with little or no acid–base chemistry background to the basic theories of solution chemistry. First, students measure the conductivity of water samples with different ionic compositions, serving as an introduction to the conductivity of solutions. Second, to simulate the neutralization reaction between acid rain and limestone as it occurs in nature, students pass a sulfuric acid solution through a column containing calcium carbonate and monitor the conductivity of the resulting solution. Students are then required to graph conductivity versus volume of sulfuric acid added to the calcium carbonate column and use the resulting plot to calculate the equivalence point. Additionally, an instructional video containing animated features was created and utilized to engage students in learning new chemistry concepts by relating chemistry to their daily lives and helping them visualize experimental setups. Significantly, the experiment has been adapted to include the use of a pH probe or multimeter to make it more accessible to K–12 classrooms and teaching laboratories without access to conductivity probes.