In this fun science experiment we will make rock candy crystals. Sugar crystals will formed on a string, a delicious creation will be seen when finished. In the process we will make a super saturated solution.
Is it possible to make a rock candy?
It is possible to make a rock candy out of sugar crystals.
- 15cm piece of cotton string
- A pencil
- A paper clip (or large plastic bead)
- 1 cup of water
- 2 cups of sugar
- A glass jar
- Tie the 15 cm piece of cotton string to the middle of the pencil.
- Wet the string and roll it in sugar giving it a healthy coating.
- Then let this dry.
- Tie the paper clip (or bead) onto the end of the string.
- Put the pencil across the top of a jar so that the string hangs down the middle of the jar.
- If it hangs down too far, roll the string around the pencil until the string is not touching the sides or bottom of the jar. The string will act as a seed for the crystal.
- Any type of jar will do, but canning jars, pint size are especially nice, they will endure the hot temperatures. Tall skinny olive jars are also nice because they don’t use up so much of the liquid
- Now that the string and pencil are ready remove them from the jar and put them aside.
- Pour the water into a pan and bring it to boil.
- Pour about 1/4 cup of sugar into the boiling water, stirring until it dissolves.
- Keep adding more and more sugar, each time stirring it until it dissolves, until no more will dissolve.
- This will take time and patience and it will take longer for the sugar to dissolve each time. Be sure you don’t give up too soon.
- Carefully pour the hot sugar solution into the jars to the top. Then submerge the paper clip and string into the sugar solution. Be sure the string hangs down in the middle of the jar.
- The Crystals above took about 2 weeks
RESULTS / ANALYSIS OF DATA
When water and sugar is mixed, it made a super saturated solution. This means that the water could only hold the sugar if both were very hot. As the water cools the sugar “comes out” of the solution back into sugar crystals on your string. The string and paper clip act as a “seed” that they start to grow on.
A rock candy is a possible experiment. The materials are easy to find. With some luck and patience a tasty scientific treat is at hand.