Chemistry Lab: Exploring the “Mentos® – Diet Coke®” Fountain

Unit 1: Matter and Change                                                                                                                                                 Chemistry

Part I: Observe demonstration of submerging 16 mint Mentos® into a freshly opened 2-liter bottle of room-temperature Diet Coke®.  Document all conditions: temperature, height of spray, remaining volume of coke, appearance of Mentos before and after the experiment.

Part II: Discussion of cause of fountain.  In small groups (2-3 students) come up with a hypothesis (or two) explaining why the fountain occurred (5-7 mins).  This should be something that your group could explore.  Groups then report their hypothesis to the class, and a list is compiled.

Part III: Experimental Design Determine one hypothesis to explore as a class.  Again in small groups each group designs an experiment or two to test an aspect of the final hypothesis.  Compile a list of these experiments appropriate for investigation in our lab.

Part IV: Experimenting Before the actual experimenting, the group will defend their experimental design, stating how they expect their experiment would be meaningful.  Then run the experiments, collecting data.

Part V: Report Each student will complete a unique report, which includes copies of his/her lab notebook sheets from the lab group work, individual notes from the class discussion, a summary of the lab group’s data, calculations (if necessary).  Most importantly, write an analysis of your experiment, explaining whether the hypothesis was confirmed or denied, and any proposed modifications to the original hypothesis.  Then in an additional paragraph discuss the results of the class’ experiments as a whole in support of the hypothesis.  Make modifications to the hypothesis based on what the class collectively learned, justifying your adjustments with evidence from the experiments.