Dry Ice is solid Carbon Dioxide (CO2) that sublimes to a gas. There is no liquid phase, that's why it's called Dry Ice! It is also -109F. Carbon Dioxide is a very common gas found in all restaurants to carbonate beverages. We used to see it in compressed gas cylinders. But now we are seeing it in Cryogenic Dewar's that store much larger volumes. CO2 alarms are a very common call now a days and hazmat teams need to be prepared to monitor for CO2.

Concepts:

Non-Flammable gas that displaces oxygen, heavier than air, dissolves in water to make Carbonnic Acid

Safety:

Safety glasses MUST be worn at all times by demonstrator and the audience.

Use tongs or appropriate gloves (Not nitrile) to grab Dry Ice, do not use your bare hands.

Do not put in your mouth.

Ensure you have adequate ventilation

Never trap the escaping gas, it must have a vent or it can build up pressure and pop.

Equipment:

• Dry Ice (Pellets are best and normally at Air Gas Linde or local gas supply)

• 5 gal. water jug with hose that fits snugly in the opening. A pool vacuum hose or shop vac hose should work

• Bowl

• Soap, glycerin (Buy at pharmacy or Amazon )

• warm water

• 4-gas

• PID

• CO2 Sensor

• Hotplate, microwave, and container for hot water, or coffee maker.

• Café tray

• Clean cotton gloves

Preparation:

• Warm some water on a hot plate or in a microwave

• Pour water into the water jug, about 4" should be good or about 1/4 of the container

• Use bottled water, soap and glycerine to make a bubble solution in a bowl.

• Also put some solution on a cafe tray

Demonstration Instructions

• Place the Dry Ice into the water jugs and you will see an instant cloud of water vapor and Carbon Dioxide gas.

• This gas will start to flow out the top of the water jug.

• Hold the hose on the jug with your hand so you hold both the hose and the jug at the same time.

• With the other hand grab the hose and place into the bubble solution and you will start to make bubbles of CO2.

• You can drop these bubbles onto clean cotton gloved hands and they will not break. You can actually bounce these around from one hand to the other. Or you can create large bubbles on the tray by putting the hose flat on the tray into the bubble solution. These will get large.

Observations:

Students can see the gas accumulation that is heavier than air when the bubbles are popped.

Learning Outcomes:

• You can take this topic for a good ride to discuss CO2 as a gas that percipates out to solid and back to a gas. You could use a CO2 fire extinguisher and spray it a wall and see the percipated CO2 fall out and then sublime.

• Keep dry ice on the table and let it sublime

• Put a piece in a balloon and tie it off. Dry Ice will fill the baloon with gas.

• Use instrumentation to talk about monitoring, gas density, ionization potential, oxygen displacement,

• Talk about the exposure values fro CO2, OSGHA Permissible Exposure Limit (PEL) is 5,000 ppm

• Oxygen displacement, rule of 5000

Chemical Disposal:

None. It iwll sublime away. The water, soap, glycerine can be disposed of in the sink.

Additional Information:

• Smaller kits can be purchased off Amazon https://www.amazon.com/Steve-Spanglers-Boo-Bubbles-Experiment/dp/B07263B8Z5

• Dry Ice will sublimate at a rate of 5 to 10 lbs every 24 hrs. when stored in a normal ice chest. Purchase just before use!

• Dry Ice can also be used for PH demonstrations, see DOT 8

• Due to the sublimation of Dry Ice it has been used for nefarious activities by kids/adults by making pressure devices. This can be dangerous and possibly against regulations for your jurisdiction.

Concepts:

Metal fires, fire extinguishers

Safety:

Safety glasses MUST be worn at all times by demonstrator and the audience

Safety shield MUST be placed in front of the audience and the demonstrator or sufficient distance

Leather gloves

Fire extinguisher

Equipment:

• 2 blocks of dry ice. You can normally by the 2" thick 10x10" flats of dry ice at Albertsons or many grocery stores.

• Magnesium

• BBQ lighter or propane torch

• Non-combustible surface

Preparation:

• Carve out a half golf ball size in one side of the block.

• Stuff the hole with magnesium ribbon

Demonstration Instructions

1. Light the ribbon and let it get going before you cap it, the magnesium will start to burn and produce intense white ultraviolet light. Then cap it!

2. Let it burn and it will glow. CO2 gas will shoot out the sides of the blocks where they are capped.

3. Once the fire is out let it cool a bit.

4. Empty the center out onto a pan and break the magnesium oxide coating and you will find a carbon ball in the middle.

Observations:

• Magnesium burns ~3000F and will burn in pure CO2. Therefore a CO2 fire extinguisher will not work!

Learning Outcomes:

• Magnesium and titanium are the most common metal fires we will encounter. You can talk about not putting water on these fires as it will create a steam explosion!

• You can cover the water reactive metals also. Column 1 with Li through Fr. We will cover those demos in flammable solids. Magnesium is slightly water reactive, its slow to occur. Unlike Calcium and the ones below it. Al oxide is not very water reactive either due to the oxide layer, but pure aluminum is very water reactive!

Chemical Disposal:

• Check your local regulations for proper disposal, but the CO2 will sublime away and the remaining carbon is not hazardous.

Additional Information: