| C6-2 | Cryophorous. |
| Purpose: | To demonstrate crystal formation. |
| Description: | A sealed glass tube has bulbs on both ends and contains liquid water. The air is pumped out so the pressure inside the tube is due only to water vapor. The water is all placed in the upper bulb while the lower bulb is immersed in a mixture of dry ice and alcohol. The vapor condenses in the lower bulb and evaporates in the upper bulb. The evaporation produces cooling, and after a short time the cooling is sufficient to freeze the remaining water. |
| References: | Mj-8 |
| Equipment: | Drinking bird and a beaker with water. |