This document provides instructions for growing ADP crystals. It involves three main steps: 1) Dissolving ADP powder in hot water to make a saturated solution, then allowing it to cool slowly. 2) Pouring the cooled saturated solution into a sealed container and letting it sit for 2-3 days, during which crystals will form as the solution cools. 3) Using existing crystals as "seed crystals" by placing them in a new saturated solution, then allowing it to cool slowly over 2-3 days to form even larger crystals that grow from the seeds. Repeating this process allows forming increasingly large crystals.

1. Procedure
to grow ADP crystals
Crystals in school competition

2. Materials
 Heat source (such as a hot plate)
 1 l beaker (or a similar container)
 100 ml water
 Glass rod
 Kitchen paper or dishcloth
 Oven gloves
 Lab thermometer (optional)

3. Procedure
First step: dissolution of ADP crystals
 Firstly, you need to dissolve the ADP powder in hot water.
1. Pour 325 gr of ADP powder in the beaker.
2. Add 500 ml of water and put to heat.
3. Stir gently to dissolve the powder.
4. Be careful with the hotplate! Avoid placing your head directly overhead
the beaker.
5. Heat until the solution boils.

4.  This is the solubility curve for our solution. Since we have disolved 325 gr in
500 ml of water (650 gr in one litre). Our solution is in point A.

5. Second step: slow cooling
 To obtain the ADP crystals the saturated solution has to be cooled slowly. To do
this we need a polystyrene container or a similar insulating container.
1. Turn the hotplate off and alow the solution to cool for 5 minutes. Now the
solution is in point B in the graph.
2. Make sure the plastic glass is inside the container.
3. Pour the solution into the the plastic glass.
4. Be careful not to burn yourself.
5. Cover the glass and the container.
6. Let it sit for two or three days. It is important not to move or open the
container during these three days.
7. After that time our solution will be at room temperatura in point C of the
graph. Crystals would have formed.

7. What happened?
 In most solutions, the higher the temperature, the more substance can be dissolved.
As the temp falls back to room temp, the solution can't support that much substance
to be dissolved anymore, so the substance has to precipitate out of the solution in
crystalline form.
 When a saturated solution is cooled down at a certain temperatura it cannot support
as much dissolved ADP as it did when it was hot and it has to precipitate the excess
out of the solution in a crystalline form, as a solid.
 The ADP molecues organise themselves in an orderly form, following a pattern.
 A crystal is just a very organised structure like the one in the picture of the next
slide that grows as the molecules of ADP precipitate in an orderly arrangement. It’s
like playing Tetris!

8.  When a solution cools slowly the molecules have more time to organise
themselves and the crystal can grow larger and better.
 If the solution is cooled quickly the ADP precipitates quickly and the crystals
are smaller. When cooled slowly the crystals are less but larger.

9. Third step: Even bigger!
 The crystals previously formed will be used as seed crystals.
 Carefully take the crystal out of the container and place it on a cloth or kitchen paper.
 Pour the liquid in the glass in a beaker. Make sure not to pour the white powder in the bottom
of the glass (gypsum).
 Clean the plastic glass.
 Put the crystal back in the plastic glass and into the polystyrene container.
 Make another saturated solution by using some more ADP and about 250 ml of water.
 Heat it until it boils.
 Let it cool for 5 minutes and pour in the glass over the crystal seed.
 Cover the glass and the container.
 Let this cool for two or three days.
 You can repeat this procedure as many times as needed.