|MadSci Network: Chemistry|
Greetings, Ashley: You should be able to find initial information on the subject of evaporation in any good encyclopedia. Some of them, such as Encyclopaedia Britannica, are accessible via the Internet (http://www.britannica.com). Be sure to check out some of the cross-links to related topics, and/or to specify a "search" or two (example to type in the search box: evaporation AND cooling). With respect to conducting experiments, this particular phenomenon is relatively easy to test. Nevertheless, a measure of caution is always necessary. One key fact about evaporation is: The amount that can occur is directly related to the surface area of the liquid that is exposed to the air. Suppose that only a tiny amount of cooling happens to the liquid; how can you measure it with an ordinary thermometer? The trick is to use a "wick". This is generally a length of fibrous substance that you partly use to surround the little bulb at the end of a thermometer. Then you dip the rest of the wick into a container of liquid. CHOOSE YOUR LIQUIDS AND THE ENVIRONS OF YOUR EXPERIMENT VERY CAREFULLY! Some readily available liquids are poisonous, flammable, and even explosive. If you dare to test a liquid like gasoline, for example, use small amounts only, and do it outdoors! Other readily available liquids are water, vinegar, rubbing alcohol, and motor oil and kerosene. A few liquids you may be able to obtain after some searching, but probably not with any greater difficulty than getting an adult involved: sulfuric acid, carbon tetrachloride, and dimethyl sulfoxide, for example. PAY CLOSE ATTENTION TO ALL WARNING LABELS! Be sure to pick a wick material that can withstand all these liquids! (You may be able to find one made from glass fibers.) The experiment consists first of recording the temperature before placing the wick in the liquid. Allow a minute to pass, giving the liquid a chance to move up the wick and into the air, taking advantage of the large surface area it provides. (Something else to research is HOW all those wick-fibers provide vast amounts of surface area for the evaporation of a liquid.) Make recordings of the temperature every minute, for fifteen minutes or so. By then any change in temperature that is going to happen will have happened. It is not necessary to test all your different liquids at the same time. Good luck!
Try the links in the MadSci Library for more information on Chemistry.