T560: Effects of Temperature – Sublimation

Introduction

The sublimation of iodine crystals and dry ice are demonstrated.

To Conduct Demonstration

1. Sublimation of Iodine Crystals (Option 1)
2. Place a closed glass tube of iodine crystals in the water.  The tube will fill up with iodine vapor.  No liquid iodine will form.
3. Heat a tall 1000mL beaker full of water to boiling.
4. Sublimation of Iodine Crystals (Option 2)
5.  Fill a florence flask with ice and place over a beaker containing a small amount of iodine crystals.  Heat on low heat over a hot plate.  Iodine will sublime and  recrystallize onto the outside of the florence flask.
6. Sublimation of Dry Ice
7. Place a chunk of dry ice into a disposable latex glove.  Tie the opening so that no gas escapes (attach a balloon to a flask with piece of dry ice in it).
8. After the glove fills with CO2, pass it around the room to show that it contains no liquid.

Demo Time: 15 - 30  minutes

Safety and Disposal 

Dry ice vapors can cause burns to exposed skin.  Wear protective gloves when handling dry ice.  Do not breathe iodine