We're playing with dry ice this year... I thought I'd share.
Frozen carbon dioxide sublimates (changes from a frozen solid to a gas) when exposed to drafts, but it changes especially quickly when exposed to hot or warm water.
Here are the rules:
- Never touch it with any part of the body. Use heavy gloves. Tongs are good, too. The ice temperature is -110F ( -78C). Cold enough to cause frostbite to your skin. (Note here: if you touch it super quickly, it won't burn you- much like touching a hot stove very quickly.)
- Never seal dry ice in a container... dry ice (as it sublimates) will expand into whatever space is available... if its contained in a sealed cooler, it could/will explode the chest. Always keep it cracked. Don't store it in a freezer, it will sublimate quickly in the air currents.
- Don't eat it. If you're carbonating a drink, wait until the ice is gone before drinking your liquid.
- Use it where there is ventilation.
As the water cools, the ice will slow its effect, so just change the water, replacing it with warm again!
Now! Let's play. Here are our experiments.
- Put a piece of dry ice in a plastic beaker of warm water with a glowstick in it for an eerie effect.
- Place a beaker with warm water and ice in a jack-o-lantern... if it's a short beaker, the gas will come out of its mouth, a tall one will allow the gas to come out of its eyes, as well.
- Place colored warm water and dry ice in a plastic beaker, and add karo syrup. The syrup is heavier than water, so it will sink and encase the carbon dioxide. Bubbles will form in the syrup and water as the dry ice sublimates, as well as oozing fog out of the jar.
- With two balloons and a plastic soda bottle - blow up a balloon and tie it off. Using tongs, place small bits of dry ice in the plastic soda bottle, then fit the balloon over the top of the bottle. To have it fill with gas more quickly, create air currents by waving the bottle back and forth, causing quicker sublimation. When the balloon is inflated, take it off the bottle and tie it off. Toss balloons into the air... carbon dioxide proves heavier when it quickly falls to the ground.
- While wearing gloves and with tongs you can touch the first balloon with a piece of dry ice... what will happen?
- Using gloves and tongs, put a small piece of dry ice inside a latex glove and tie it. Watch it inflate, just like a balloon.
- We saw this one at the chemistry science fair just recently... Place dry ice in the bottom of an aquarium, and then blow bubbles into the aquarium... they'll float! They should also grow until they're too heavy and then sink...
- You can also do this with dry ice and warm water in the bottom of the tank, with the same results-- the bubbles will float on top of the carbon dioxide.
- Fill a plastic beaker with warm water, put in a piece of dry ice, and then add some dish soap. The ice will spill bubbles over the sides, the bubbles will carry the fog.
- For a noisy experiment, hold a warm spoon firmly in your hand, then press it onto a piece of dry ice. The spoon (or other metal) will scream loudly as the spoon causes the dry ice to sublimate quickly-- the pressure of the gas pushes the spoon away, then it makes contact again, causing a vibration... thus, a noise.
added post experimenting:
- also try dropping a piece in a glass of milk (it doesn't need to be warm)
- we put a few pieces (that we could fit) into the opening of a balloon, and immediately tied the balloon. It blows itself up as the ice sublimates. Then compare it to a regular co2 balloon, and it falls much faster and heavier!