Chemistry Everyday for Everyone
Secondary School Chemistry
Distillation Apparatuses Using Household Items Danielle R. D. Campanizzi, Brenda Mason, and Christine K. F. Hermann* Department of Chemistry and Physics, Box 6949, Radford University, Radford, VA 24142; *
[email protected] Distillation is a difficult technique to visualize and even harder to demonstrate without specialized equipment. However, a suitable distillation apparatus easily illustrates the phenomena of evaporation and condensation. Distillation has been described in children’s books using a system similar to a simple distillation apparatus found in an organic chemistry laboratory. One description (1) includes a Pyrex flask as a distilling flask, glass tubing as a condenser, and a cup as the receiver. Another method (2) uses a tea kettle, rubber tubing, and a bottle placed in ice. A homemade rainstorm (3) can be created by placing an inverted jar over the spout of a tea kettle. The concepts of evaporation and condensation have been illustrated by using stretched plastic weighted down by a rock, with a cup below the plastic (4, 5). This apparatus is placed in the ground. An illustration of Old Faithful is achieved by placing an inverted funnel in a Pyrex dish of boiling water (6 ). We have developed two setups to illustrate distillation, using easily obtainable household items. From these apparatuses, not only distillation but also evaporation, condensation, and other processes can be readily demonstrated. All glassware should be thoroughly cleaned before this experiment is performed. Distillation Apparatus A A distillation apparatus is illustrated in Figure 1. A babyfood jar is placed on a wooden block inside a quart jar. The quart jar is then filled with water to the top of the wooden block. Food coloring is added to the water. The quart jar is placed on a trivet in a shallow pan. The pan is filled with water so that the bottom of the quart jar is immersed. A funnel, lined with aluminum foil and filled with ice, is placed over the mouth of the quart jar and centered over the baby-food jar. The apparatus is placed over a source of heat such as a hot-plate or stove burner. Distillation Apparatus B Another distillation apparatus is illustrated in Figure 2. CAUTION: Since acetone is flammable, no flames are allowed. Also, acetone fumes are harmful and this experiment should only be done in a well-ventilated space. Cut a hole, large enough for a straw to pass through, into the lid of a glass salad-dressing bottle. Seal the ends of two bendable straws together with modeling clay. With modeling clay, seal one end of the two straws into the hole in the jar lid. Place one cup of acetone into the salad-dressing bottle and attach the lid. Place the bottle gently inside one of the wide-mouthed glass quart jars. Position the other end of the straws so that it is over an inverted Styrofoam cup,
which is inside another glass quart jar. Pour three cups of hot water into the glass jar containing the salad dressing bottle. Rubbing alcohol may be used as a substitute, but it has a higher boiling point and it may be difficult to keep it boiling with hot water. Since rubbing alcohol does not dissolve Styrofoam cups, there is no reason to place an inverted Styrofoam cup in the second quart jar. Results and Discussion In distillation apparatus A, the water inside the quart jar will boil shortly after the water in the pan begins to boil. The water vapor inside the quart jar condenses on the chilled aluminum foil and drips into the baby-food jar. The use of colored water in the quart jar enables the students to see a difference between the original colored water and the “purified” water after distillation. In terms of the more conventional methods of distillation, the quart jar corresponds to the distilling flask, the aluminum foil containing ice acts as the condenser, and the baby-food jar is the receiver. The water evaporating from the quart jar condenses on the cold foil. In distillation apparatus B, the acetone will begin to boil a few minutes after the hot water is added to the quart jar. The acetone vapors will condense in the straw and then drip onto the Styrofoam cup and soften it. Rubbing alcohol will be more difficult to get to boil. NOTE: If the salad dressing bottle is too large, too much time will be wasted waiting for the acetone to boil and the water bath will cool before the acetone reaches its boiling point. Conclusions The entire distillation apparatus A is safe to use. Once it is set up and distillation is occurring, the apparatus is selfcontained. This apparatus can be easily set up as a demonstration in front of a class and the difference between the solution and the distillate is easily seen. Since straws are used in distillation apparatus B, it is much preferred to the tea kettle method (2). The tea kettle method employs rubber tubing that has no means of support and could possibly touch the source of heat. It would be difficult to keep the tubing from kinking, whereas the use of straws keeps the “condenser” rigid. The softening of the cup with acetone gives visual evidence that not all liquids are water and that different liquids have different boiling points. In summary, both apparatuses are simple cost-effective ways of demonstrating distillation, evaporation, and condensation. They would be ideal to use in elementary and middle school classrooms when explaining these concepts. The equipment to build these apparatuses are readily available at local department, grocery, or hardware stores.
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Chemistry Everyday for Everyone
Literature Cited 1. Challand, H. J.; Brandt, E. R. Science Activities From A to Z; Children’s Press: Chicago, 1964. 2. Arnov, B. Water Experiments to Understand It; Lothrop, Lee, and Shepard: New York, 1980; pp 31–34. 3. Wyler, R. The First Book of Science Experiments; Franklin Watts: New York, 1952. 4. Ravensburg, O. M. V. Science Projects for Young People; Van Nostrand Reinhold: New York, 1967; p 95. 5. Brown, R. J. 200 Illustrated Science Experiments for Children; Tab Books: Blue Ridge Summit, PA, 1987; pp 55–56. 6. Herbert, D. Mr. Wizard’s Science Secrets; Hawthorn Books—Popular Mechanics Company: Chicago, 1952; pp 228–229.
funnel containing ice in foil quart jar containing water
condensed water droplets
baby food jar block of wood
water level
pie pan with water trivet
Figure 1. Distillation apparatus A.
modeling clay
bendable straws
acetone hot water acetone styrofoam cup
Figure 2. Distillation apparatus B.
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Journal of Chemical Education • Vol. 76 No. 8 August 1999 • JChemEd.chem.wisc.edu
