Transcript COOL ICE

COOL ICE
DR SAADOUNE
Dr Saadoune
c
direction
b
a
100
Å
Helix pitch:
50 Å
They may look similar !!! But they are
different !!
Water
Solid
0
Freezing point
100
Liquid
T oC
Gas
Boiling point
Carbon Dioxide
Solid -78
Sublimation point
Gas
0
T oC
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
Experiment 1 Singing Spoon
Experiment 2 Fog Effects
•
First dip the metal spoon
• Use a plastic forceps (not your
into warm water. Then hold
hands) to place two-three pieces
the warm spoon by its handle,
of dry ice into warm water. What
and press it firmly against a
do you observe happening? Can
chunk of dry ice. What do
you suggest an explanation?
you observe happening?
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 ?
Let’s make a fizzy drink !!?
Carbon Dioxide Chemistry
Lower carbon
dioxide levels
More shells
Results are still inconclusive
Higher carbon
dioxide levels
Less shells
Changing State
Which box represents which state?
A
B
C
?
D
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