Whoever thought that chemistry could be fun? Not anyone who has ever taken organic chemistry. Forget that, because making rock candy is an easy and fun way of demonstrating an entropy decrease – part of the Second Law of Thermodynamics – in your kitchen!
Ingredients:4 cups of sugar2 cups of water
Tools of the Trade:a small sauce pana wooden spoona candy thermometera small, clean jara measuring cupcotton stringa weight to hang on the string such as a washer or nailwaxed papera pencil
Directions:
1. Heat the water in the saucepan over medium-high heat until the water comes to a boil.2. Completely dissolve the sugar in the boiling water, stirring it continuously with the spoon until the solution becomes clear and reaches a rolling boil.3. Remove the sugar-water solution from the heat and then carefully pour it into the jar.4. Cover the jar with a small piece of waxed paper.5. Tie the string to the middle of the pencil – if necessary, use a piece of tape to secure the string.6. Suspend the prepared string in the solution and let it sit at room temperature undisturbed for several days. You can check each day to see how much your crystals have grown. Do not touch the jar.7. After about seven days, when the crystals on your string are clearly defined, the rock candy is ready to be eaten.
The basic idea of this recipe is to boil water and sugar until the sugar can no longer dissolve. As heat leaves the jar, it cools and crystals form. This is where the Second Law of Thermodynamics comes into play. As the heat goes out, the molecules slow down and are able to stick together. In addition to rock candy, other types of candies such as bonbons and gum drops contain crystal coatings similar to the process used to create rock candy. Go ahead and watch your food grow. Gorode can be reached at kgorode@campustimes.org.
