Dry Ice:
Independent Grocers 3 Coulthard Crt Alice Springs ph 8952 2766
$7.20 per kg. Comes in 2 kg blocks.
Boc
57-59 Elders St comes in pellets $8.90 kg - when excess available

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dry ice experiment in hot water
dry_ice.jpg
Frozen CO2. Comes in blocks

















Dry Ice: Safety

http://www.praxair.com/praxair.nsf/AllContent/6AEF77AEC129FA0B85256C72006A4DD7?OpenDocument&URLMenuBranch=8E0340F7CB2710A18525706F005112A9


Some useful sites
http://outreach.rice.edu/~dgabby/science/dry_ice/dry_ice.htm
http://www.dryiceinfo.com/science.htm
http://tlc.ousd.k12.ca.us/~acody/Dry_Ice.html

DRY ICE EXPERIEMNTS

What's Dry Ice?
Dry ice is frozen Carbon Dioxide, or CO2, which is a gas under standard temperature and pressure conditions. The atmosphere contains about .035% of this gas. CO2 is a greenhouse gas, which means it absorbs light at infrared wavelengths. An increase in the concentration of this gas would, some scientists believe, cause an increase in the atmosphere's average temperature. The high concentration of CO2 in the atmosphere of the planet Venus is said to contribute to that planet's high average temperature.

This process is called sublimation. 1 pound of dry ice, when it "sublimes" (turns to gas) will produce 250 litres of gas at atmospheric pressure, enough to fill 125 2-litre bottles. That's a lot of gas!
Handling Dry Ice
Due to its extremely cold temperature (-78.5oC, or -109.3oF), dry ice can cause damage to the skin if handled. Use tongs or insulating gloves when handling dry ice. It is also important when crushing or grinding the solid not to get any of the dust into your eyes. Wear protective goggles.


Popping Film Cans
A fun activity vividly illustrates the sublimation process. Place a piece of dry ice into a plastic 35mm film container - the kind that has the snap - on cap. Then wait. The cap will pop off, and sometimes fly several meters. The clear Fuji brand containers shoot farther than the gray and black Kodak type. Warn anyone performing this experiment not to aim for anyone's eyes.

Inflate A Balloon
Grab an uninflated balloon and force the neck open with the index and middle fingers of both hands, stretching the balloon open. This will allow you to drop in one or more pellets of dry ice. Tie the balloon closed. Set aside, and observe for awhile. Better yet, drop the balloon into a pond or swimming pool. This will help supply heat to the dry ice. At first, the balloon will sink, but soon, as it begins to inflate, it will rise to the surface.
If you manage to put enough dry ice into the balloon, it will eventually reach the bursting point. Again, this is lots of fun if the balloon is in a pool.

Singing Spoon
Press a warm spoon firmly against a chunk of dry ice. The spoon will scream loudly as the heat of the spoon causes the dry ice to instantly turn to gas where the two make contact. The pressure of this gas pushes the spoon away from the dry ice, and without contact, the dry ice stops sublimating. The spoon falls back into contact again, and the cycle repeats. This all happens so quickly that the spoon vibrates, causing the singing sound you hear.

Fog Effects
When you place dry ice into some warm or hot water, clouds of white fog are created. This white fog is not the CO2 gas, but rather it is condensed water vapor, mixed in with the invisible CO2. The extreme cold causes the water vapor to condense into clouds. The fog is heavy, being carried by the CO2, and will settle to the bottom of a container, and can be poured. You can produce enough ground - hugging fog to fill a medium sized room with a pound or so of dry ice. Do not allow anyone to lay down in this fog, or allow babies or pets into it, as CO2 gas does not support life. Dry ice fog allows low powered laser beams to be seen

Bubbling gas
Who would have guessed that you could have this much fun with soapy water and a chunk of dry ice? Fill a tall glass or plastic cylinder with warm water and add a squirt of liquid dish soap. Use gloves or the tongs to place a piece of dry ice into the soapy water.
Instead of the dry ice just bubbling in the water to make a cloud, the soap in the water traps the carbon dioxide and water vapor in the form of a bubble. The students will see the bubbles climb out of the cylinder of warm, soapy water and explode with a burst of "smoke" as they crawl over the edge.
Add some food coloring to the water to make the demonstration more colorful. If you want to give the exploding suds an eerie glow, drop a glowing lightstick into the water along with the dry ice. The lightstick will give the bursting bubbles an eerie look.

Floating Bubble Variation on the Youtube version.
You'll notice that when you add dry ice to water, the cloud of carbon dioxide and water does not go up into the air, but instead falls towards the ground. Why? This cloud-like mixture of carbon dioxide and water is heavier than the surrounding air. You'll use this little piece of science trivia to perform the amazing Floating Bubble trick.
A small fish aquarium works well for this activity. Fill the bottom of the aquarium about an inch deep with warm water. Use gloves or the tongs to add a few pieces of dry ice. Of course, the dry ice will begin to smoke turning into carbon dioxide and water vapor.
Using a bubble wand and a bottle of bubble fluid, blow a few bubbles into the aquarium (it's a little difficult so be patient). To everyone's amazement, a few bubbles will appear to float in mid-air in the aquarium. The bubble is really just floating on a cushion of invisible carbon dioxide gas.

Super Freeze
Add Dry Ice to a beaker of methylated spirits (denatured alcohol). The alcohol does not freeze like water would do so the whole thing becomes a super cooling liquid. Flowers and green leaves will freeze in just a few seconds and can then be broken and snapped apart.