PSLE: Dear students, Do not STRESS; Do your BEST; Forget the REST. "You may never know what results come of your action, but if you do nothing there will be no result.” ~ Mahatma Gandhi.

How to make crystals from a solution?

What is a solution?
When some substances - salt, sugar or bicarbonate of soda, for example are mixed with water, they dissolve and make a mixture called a solution.

When salt dissolves in water, it seems to disappear, but actually not as we could taste it. In the water salt breaks into tiny atoms that are too small to see.

Now how can we make crystals from a solution. Here is a smal experiment you can do at home. 

bicarbonate of soda
hot water
a glass jar
pipe cleaner
a teaspoon
a pencil

  1. Stir the bicarbonate of soda into half a jar of hot water, 1 teaspoon at a time. This makes a solution.
  2. Stir the solution until the soda disappears before you add the next teaspoon.
  3. Keep adding the soda until it stops disappearing. This means the solution is saturated and can dissolve no more soda.
  4. Bend one end of a pipe cleaner into an interesting shape like' ?'. Balance the pencil on the jar and suspend the pipe cleaner in the solution.
  5. The next morning you could see sparkling crystals on the pipe cleaner.
Note: Best result could be achieved if done slowly and with patience.

How this happens?
Hot water can hold more soda molecules than cold water. As the water cools down, molecules of soda leave the solution. The only place they can go is to attach themselves with each other and to the pipe cleaner. They cluster together on the pipe cleaner to become bigger crystals. Can examine the many different shapes of crystals through a magnifying glass.