Transcript Dry Ice Background - Mrs. Stock's Science Class

Dry Ice Background
• Dry ice is carbon dioxide in its solid state.
• Remember…dry ice sublimates instead of
melting.
• Carbon dioxide is found in
the earth's atmosphere
• Humans exhale carbon
dioxide gas and plants
use it for photosynthesis.
• Carbon dioxide is a colorless,
odorless, and tasteless compound.
Dry ice is -109 degrees Fahrenheit
Safety For Dry Ice Lab
• Do NOT touch dry ice with your bare hands, it
can damage your skin. Dry ice will BURN
exposed skin!!!
• Use the plastic tongs to touch and move the dry
ice.
• Wear your safety gear: aprons, goggles and
gloves
• Long hair must be
pulled back.
• Do NOT inhale
the gas.
Safety (cont.)
• Use caution when lighting the candle.
• Make sure the area you work in is well
ventilated. Do NOT close the doors.
• Do not place dry ice or dry ice and water in a
sealed plastic bottle or thin glass bottle. It will
explode. People can be severely injured. It is
against the law and it is a felony.
Dry Ice Lab
• Problem: How will the dry ice react in the following
experiments?
• Hypothesis: Your educated guess to the problem
above (1 hypothesis per experiment…there are 4).
• Procedures: Each individual lab within this activity
has its own procedure. We will step through these as
a class using this presentation. No one is allowed to
move ahead until we are all ready.
• Answer questions for each experiment. I don’t know
is not an acceptable answer. Make an educated
guess.
Experiment 1: Screaming Metal
Write Hypothesis and Results only
• Materials: lab spoon, Petri dish, dry ice.
• Procedure: Place the metal spoon against
the dry ice in the Petri dish.
• Hypothesis: If…then….
• Results: What happens? Why do you
think this happens?
• Be careful not to let the spoon get too
cold, you could get frost bite.
Experiment 2- Magic Fire
Extinguisher
• Materials: beaker, dry ice, match, candle,
clay, small pie tin.
• Procedure: Place the dry ice in your
beaker. Light the match and light the
candle. Place the candle near the dry ice.
• Hypothesis: If…then….
• Results: What happens? Why do you think
this happened?
Experiment 3 – Spooky Fog
• Materials: 100 ml of hot water , glass
beaker, dry ice.
• Procedure: Place 100 ml of hot water into
the beaker. Add some dry ice.
• If….then…
• Results: What happens? Why do you think
this happens?
Experiment 4 – Soap Ooze
• Materials: the spooky fog, 10 ml of liquid
soap.
• Procedure: Add the10 ml of soap to the
spooky fog experiment.
• If…then…..
• Results: What happens? Why do you think
this happened?
Conclusion – Write all answers
together in paragraph form
1. What is sublimation and how is it
different from melting?
2. What is needed to cause a substance to
sublimate?
3. Where is the thermal energy coming
from to cause the dry ice to sublimate?
4. Is sublimation a physical or chemical
change? Explain your answer.