If there are several groups of observers then we may determine a group average of the period as well as an overall grand aveage. The spread of these measurements lets us know something about their validity. This also teaches us something about measurement and statistics.
Experimental Setup
Listed below are movies of the Belusov-Zhabotinsky reaction at three different temperatures, 22 C, 40 C, and 74 C. These may be used to develop experimental data if it is inconvenient to actually run the reaction. The movies have been digitized. 74C data shown in Experiment 3.
Review laboratory safety and techniques
First set (and measure) the temperature of the reaction mixtures in the neighborhood of 25C or 77F. After measurements the temperature may be raised to near 40C and then 74C.
Mix the three solutions in a large beaker placed on a magnetic stirrer and at the time when complete mixing has occurred start timing the color change. Pick a color of interest, say blue, and mark the time of the most intense color. Record these times and enter them in a spread sheet.
Data Treatment
Each group should have collected three sets of data for a number of time periods during the extent of the oscillating reaction. Each observer should average their total set of times and each group should make an average of each period time. An average and an standard deviation should be recorded. The easiest way to do this is to use a spread sheet on a computer.
For a more sophisticated discussion of data analysis go to statistics