Grades 9–12.
Determine the concentration of vitamin C in fruit juice quickly and easily in this microscale experiment. An excellent opportunity to perform an oxidation-reduction titration and learn how chemistry is used to test common products. Students initially titrate known solutions of vitamin C and plot a calibration curve. Students then titrate their fruit juice and determine the concentration of vitamin C using their calibration curve. Because each fruit sample takes just minutes to titrate, students can complete multiple trials in 1 class period. Encourage students to test different types of fruit juices and different brands. Let students test how stable vitamin C is to heat and air using conditions they choose. This experiment gives students practice mixing solutions, performing microscale investigations, graphing data, and writing and balancing chemical equations - including oxidation and reduction half-reactions. Fruit juice not provided. Materials are sufficient for 30 students in teams of 3.