THE EXPERIMENT--VOLTA'S PILE
Now let's test our ability at writing a lab report about a related experiment. This diagram and the experiment it describes is taken from "Experiments in Electrochemistry," by Giorgio Carboni, translated by G. L. Stuart--the web site is listed on the acknowledgments page of this tutorial. This experiment is like one that Volta did in order to try to increase the power of the electric current, after he had demonstrated with his cell experiment that two different kinds of metal could produce electricity, thus explaining what caused those frogs' legs to move. Let's imagine that he used a voltmeter, labeled "V" in the diagram--in his day the device used would probably have been called an "electrometer." What the diagram shows is a pile--a stack of things one on top of the other--consisting of a series of six layers of copper and zinc, each copper-zinc pair separated by paper soaked in an "electrolyte," another term that probably came into existence some time after Volta did his experiment. The top layer, a strip of zinc, is connected by a wire to the negative pole of the voltmeter, and the bottom layer, a strip of copper, is connected to the positive pole of the voltmeter. If the needle on the voltmeter moves to the right from its zero mark on the left, then the experiment supports Volta's hypothesis that by using several pairs of metal strips he could increase the resulting voltage by a multiple of the number of copper-zinc pairs he used. In fact, this is indeed what happens when this experiment is carried out--indeed the voltmeter will record slightly over 6.6 volts, 1.1 volts for each of the six copper-zinc pairs (1).
Imagine that you are Volta, and you have just done the above experiment. Now you want to write it up in the form of a lab report. The following interactive portion of this tutorial will test your ability to identify the main ideas of each of the basic parts of the lab report. In an actual lab report these main idea statements might have to be further elaborated.