cool ice dr saadoune. dr saadoune a b c direction 100 Å helix pitch: 50 Å
TRANSCRIPT
Dr Saadoune
ab
c direction
100 Å
Helix pitch:50 Å
They may look similar !!! But they are different !!
Solid Liquid Gas0 100 T oC
Freezing point Boiling point
Water
GasSolid 0-78 T oC
Carbon Dioxide
Sublimation point
Experiment 1 Singing Spoon
• First dip the metal spoon into warm water. Then hold the warm spoon by its handle, and press it firmly against a chunk of dry ice. What do you observe happening?
Experiment 2 Fog Effects
• Use a plastic forceps (not your hands) to place two-three
pieces of dry ice into warm water. What do you observe happening? Can you suggest
an explanation?
Experiment 3 Cool glove !!• Place some pieces of dry ice into a thin latex glove. Tie off the end of the glove,
shake it gently. What is happening? Explain using
your ideas about sublimation.
Experiment 4 Super bubbles!!!
• In you beaker, place some warm water and one drop of a detergent, mix them well with a spoon. Now add one spoon full of dry ice into the beaker.
What do you see happening ?
Must wear safety goggles all the time.Must be standing all the time.
Do not touch dry ice with your hands (use a plastic forceps)
Hot objects
Let’s make a fizzy drink !!?
Carbon Dioxide Chemistry
Higher carbon dioxide levels Less shells
Lower carbon dioxide levels More shells
Results are still inconclusive
A
D
B
C
Changing StateChanging StateWhich box represents which state?
What are the changes between the different states called? Do you know all 4?
?
In your books summarise the four experiments you
carried out Experiment No Observation Explanation
Keywords: Sublimation, heat energy, carbon dioxide, particles, vibration