Tick Tock, a Vitamin C Clock

In this Activity, students make a chemical clock using chemicals found in the supermarket: vitamin C tablets, tincture of iodine (2%), hydrogen peroxide (3%), and liquid laundry starch. They investigate what happens to the speed of the clock when the reactant solutions are made more or less dilute. This Activity can be used to explore reaction kinetics, and in particular the effect of reactant concentrations on the apparent rate of a reaction. It can also be used in a discussion of redox chemistry, the descriptive chemistry of iodine, and the chemistry of vitamin C.