Materials:

• A plastic glass

• A polystyrene box

• Camping gas

• A precipitate pan (½ litres at least)

• A rod of glass

• A thermometer

 

Procedure:

• The dissolution of the crystal:

1. Pour 162,5 g of phosphate monoamonico in the container it has been chosen.

2. Pour 250 ml of water in that container.

3. Pour 2 g of colouring.

4. Put the container in the camping gas to heat up it.

5. To calculate the temperature, put the thermometer in the water.

6. Stir slowly, until the salt got dissolved.

7. Stay heating it up, until the dissolution got evaporated.

 

• The refrigeration of the crystal.

1. Turn off the camping gas and let the dissolution cool for 5 minutes (to manipulate it better).

2. Put a plastic glass in the polystyrene box.

3. Pur the dissolution into the plastic glass, with a lot of care.

4. Cover the plastic glass and directly, cover the polystyrene box, too.

5. Let it in room temperature, unopened.