|
|
|
|
|
|||
|
|
|
|||||
|
|
|
|||||
|
|
|
|
||||
|
|
|
|
|
|
|
|
Experiment 2 : Properties of Water | ||||||
Question: Which explanation—the tiny-opening hypothesis or the kinetic-molecular theory—best explains the kind of liquid that forms on the outside of a glass? Background: The tiny-opening hypothesis may be used to explain where drops of liquid on the outside of a glass come from. The tiny-opening hypothesis predicts that the liquid on the outside will be the same as the liquid on the inside. The kinetic-molecular theory may also be used to explain where drops of liquid come from. But the kinetic-molecular theory says that the liquid on the outside will be water, no matter what is inside the glass. To find out which explanation best explains where the liquid comes form, you can do an experiment to test the prediction made by each explanation. Materials: 4 glasses, salt, sugar, soda pop, vinegar, ice cubes. Procedure: Put water in two glasses. The first glass should have salt mixed into the water. The second glass should have sugar mixed into the water. In a third glass put soda pop, and in the fourth glass put vinegar. Add four ice cubes to each of the four glasses. Taste the liquid in each glass. Write down a description of each taste. After a minute or so, drops of liquid will form on the outside of the glasses. You can readily observe the drops that form on the glass. When drops form on the outside, taste them. Record the taste for each glass next to the descriptions of the tastes of the liquids in the glasses. Upon completion, answer these questions:
Experiments 1-2 are based on experiments found in the following sources: Bernstein, L. (1999). Globe Biology. Upper Saddle River: New Jersey, 671pp. Magnoli, M.A., Shymansky, J.A., Blecha, M.K, Holly, J.C. (1985). Experiences in Physical Science. Laidlaw Brothers: A Division of Doubleday & Co., Inc., 592pp.
|
||
 |
© Copyright
NC State University 2004 Site design by Rosa Wallace Rev. RW 5/16/05 |
 |