From: Gail Peiterson <peite@punahou.edu>
To: "'Pinhole Listserv'" <pinhole@exploratorium.edu>
Subject: Christmas Experiment
Date: Fri, 12 Dec 1997 10:51:10 -1000
Well this is my first attempt at sending something to the Pinhole List so here goes nothing. This is a chemistry experiment that anyone can do for the holidays.
A Christmas Chemistry Experiment
Purpose: To observe the effect of temperature and torsion on the visible configuration of certain groups of molecules.
Apparatus: 600 ml beaker, graduated cylinder, Bunsen burner (with ring stand & ring & wire gauze), or hot plate, stirring rod, 150oC, thin sheets of elemental aluminum, paraffin coated paper, newspaper to cover work area. *This should be new equipment or substitute kitchen equipment of comparable measurements, do NOT use previously used lab equipment for this lab.
Chemicals/solutions: sucrose (s), concentrated glucose solution (l), water, potassium hydrogen tartrate (s), extract from peppermint plant (l), hydrated vegetable oil, consumable color altering solution
Procedure:
1. Using a 600 ml beaker and a stirring rod, thoroughly mix 225 g of sucrose, 75 ml of concentrated glucose solution, 75 ml of water, and 1 g potassium hydrogen tartrate.
2. When a uniform heterogenous mixture is achieved, subject the mixture to intense heat from the nearest source of burning methane. (Or hot plate if no burning methane available.)continue to boil the mixture, distributing the heat application evenly. During this operation, avoid stirring because any external agitation will be detrimental to the desired effect.
3. The viscosity is directly proportional to the quantity of heat. This is an important factor in determining the end product of the reaction. When the thermometer reaches 132oC, a sufficient quantity of heat has been added. Extinguish the burning methane or stop the flow of electrons to the hot plate.
4. Add extract of the peppermint plant, approximately 2 ml, and stir. Pour one half of the mixture on a thin layer of elemental aluminum which has been lubricated with the hydrogenated vegetable oil. To the portion remaining in the beaker, add 1 ml consumable color altering solution and then pour the mixture onto another piece of lubricated paraffin coated paper. Also by friction, convert from solid to liquid some of the hydrogenated vegetable oil in the palms of your hands.
5. When the mixture has cooled, work it to counter tensile strength of both portions. Continue to stretch until the honey-colored portion becomes white. Divide each color into four segments approximately 20 cm each. When ready combine one segment of each color. Do so with torsion. Place the distorted object on a clean section of the lubricated elemental aluminum sheet and shape in the form of a J tube. Allow this remain undisturbed until the viscous J tube becomes rigid in this position. Clean up all supplies and the work area while this occurs.
Conclusion: This experiment may be summarized by the critical analysis of the following question: How do your results compare with the commercial product of the same species?
This experiment is fun to do but requires setting aside a set of glassware just for food labs or going to your local thrift shop for used glass measuring cups in metric (cover other side with tape)
and old glass corning ware pots etc instead of beakers. The only thing I had to buy new were candy thermometers. It is possible. This recipe makes 4 good size candy canes but you can also clip the 4 canes into bite sizes pieces for the entire class with a good pair of kitchen scissors lubricated with margarine. Then each kid gets a sample & the cost is less. Hope you have time to try. Share any ideas you have. Aloha from sunny Hawaii..... We are having a cold snap here....Wind chill factor for today is 63 :)