Water as solvent 2: Grow crystals

Sugar is available in many different varieties and shapes. In order to produce sugar cubes, granulated sugar is moistened, pressed into cubes and then dried again. Candy is larger sugar crystals, which are made from brown or white sugar. In the following experiment you will try to grow sugar candy from sugar cubes.

Experiment

         1.     Put on the left-hand pan four lumps of sugar.

2.     Balance the scales by carefully adding the necessary amount of water from the syringe to the right-hand pan. Record the amount of water required for balance.

3.     Place the sugar in the tea light cup and add 5 mL of water....                               more see below

4.     Dissolve the sugar with stirring and heating on the candle burner.

5.     Transfer the solution with the pipette into the ampoule and stopper it. Puncture the stopper, and push the toothpick through it so that it dips into the sugar solution.

6.     Remove the stopper with the toothpick again and sprinkle the wet sticky toothpick with a few grains of sugar.

7.     Allow the granules to dry while the sugar solution cools and then replace the cap so that the toothpick is back in the solution.

8.     Leave the ampoule until the next class undisturbed in a safe place.

 

Tasks

1.     Write down your observations and explain them.

2.     Determine how many grams of sugar you dissolved in about in 5 mL of water.
1 mL of water weighs 1 g.

3.     Look on the internet for the solubility of sugar in water as a function of temperature.

4.     What is a saturated solution? Explain.

5.     Why is the dissolution process aided by heating the water?
Look at all the running processes on particle level.

First published: 17.04.2014                                                                   Last modification: 15.05.2014