http://www.straightdope.com/mailbag/mdryice.html
As of right now, you are my favorite person in the world.
It occurred to me once, during an early-morning lab session following an all-night lab report writing session, that there is a conspiracy among the media and high school science teachers designed to seduce impressionable young people into becoming science majors by deluding them into thinking they will be permitted to play with dry ice and liquid nitrogen. This is not the case.
However, the rare opportunity does arise when dry ice is available, and invariably some unauthorized research will occur.
Dry ice in itself is not a particularly fun substance; it is only entertaining when made to sublime more rapidly than it does in air at standard temperature and pressure.
I therefore suggest the following experiments, written in journal style for your reading pleasure:
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To 100 mL of solvent at room temperature was added one pellet of dry ice and the rate of sublimation was recorded.
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To 100 mL of water at temperatures ranging from 0°C to ~80°C was added one pellet of dry ice and the rate of sublimation was recorded.
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A pellet of dry ice was placed in the bottom of a stainless steel sink and subjected to the stream of a wash bottle.
The most fun part for me was using different solvents. Acetone and ether are particularly interesting, especially when warm.
Of course, these experiments should only be conducted in a fume hood while wearing appropriate safety equipment, in the absence of supervision.
I never got to try the soda-bottle thing, since I never brought an appropriate container for stealing dry ice to the lab. But I did once pour methanol and ether into a beaker of hot water (by accident; I was really tired). The explosion was really pretty, especially the globules of flying hot poison that came within a couple inches of me before being sucked up into the fume hood.
I’m not pleased with this passage. Considering the administration’s intense fear of legal liability, I am surprised that a Staff Report would be allowed to contain instructions for, and a sort of ironic encouragement to, commit a potentially dangerous felony.
Roches, I don’t condone any unsafe use of dry ice, but why would you bother stealing it from the lab? You can buy dry ice at grocery stores.
(However, I haven’t seen liquid nitrogen at any grocery stores yet. Maybe I’ll check the super-Walmart next.)
Obviously, you have never played dry ice hockey! (It’s sort of like air hockey – you use the dry ice as the puck, as it floats on a cushion of outgassing CO[sub]2[/sub]. This works best on a warm floor.)
I’ve never seen it in grocery stores here, but I suppose there must be some way of getting it.
I’ve never played dry ice hockey. It kind of reminds me of ‘eraser hockey’ that the kids who didn’t grow up to be scientists used to play in school. =P I think there was an urban legend that some kid had lost an eye playing eraser hockey, which the teachers loved to repeat.
I’ve hit dry ice around with a ruler on the lab bench, though; it’s fun, especially because lab benches are very smooth. I guess that constitutes solo dry ice hockey. It’s also a great high-school physics problem: “assuming a frictionless surface and neglecting air resistance…” =)
Of course, I don’t condone the recreational use of dry ice. Dry ice is for shipping expensive burgers cross-country and for giving the kinetic product of the enolization of carbonyl compounds with LDA.
Behold, for I am the master of dry ice mis-use! The following time-less, classic hi-jinks are undoubtedly duplicated daily in labs world-wide, and come in handy when there’s time to kill waiting on that gel to finish retrophoresing:
(let me first add this disclaimer: any confinement of dry ice in a closed container can be dangerous and/or painful…I’m surprised I still have all my fingers after pulling some of these stunts.)
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Load up a half-dozen 1.5 ml snap-top plastic centrifuge tubes (“eppies” for those in the biz) and surreptitiously drop them under the chair of a lab-mate engaged in intense concentration. Fire crackers without the fire! The tricky part is getting them all loaded and placed before they explode.
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Place a flat slab of dry ice on a flat metal tray. This results in a high-pitched scream from the outgassing between the two surfaces and the cooling of the metal.
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Fill a 1 liter graduated cylinder with a soap/warm water mix and drop in a generous chunk of dry ice and you get a soap-bubble fountain. Wheeee!
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Pour some of your favorite hard liquor (or, for the daring, some of that 70% EtOH sitting in the wash bottle by the sink) onto the surface of a slab of dry-ice. Quickly chomp down the gel-like liquor-sicles before they melt in your fingers.
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Put chunks of dry ice in a latex glove. Tie glove closed. Oh the hilarity! Now you’ve created an ever-expanding (until it pops) udder to harrass your lab mates with. Moooooo!
And to think, as a science teacher, I’m now in a position to pass down these tidbits of time-wasting wisdom to generations of future scientists. Be afraid…
Holy shat.
And all I ever did with the stuff was to make boiling, steaming purple alcoholic punch in a trash can.
It is possible to make a fine sherbet with liquid nitrogen, although obtaining the stuff is tricky, and you DO want to wear the appropriate protective gear. My teacher demonstrated this by taking a raw piece of beef, cut into a strip… flapping it around, to show everyone how limp and thawed it was… dipping it VERY briefly into the liquid nitrogen, with tongs… waving it around, to show everyone how stiff and frosty it was…
…and then briskly rapping it against the edge of the table.
Watching raw beef shatter is a most instructive experience. Makes you think about fingers and toes.
We responded by swiping the canister shortly after class. But we were extremely careful with the stuff while we made sherbet and played with the remaining liquid nitrogen, afterwards…
If you want to have fun with dry ice and be educational at the same time, you can make comets. I don’t remember the proportions exactly, but you mix crushed dry ice, water, dirt, and glass cleaner, and form it into snowballs. Great for when you’ve got a Scout group visiting the university, or somesuch, and if the kiddies are all wearing gloves, they can help out!
One time I got some dry ice. I also had some mercury and some fairly pure acetone. Duplicating the science museum demo of freezing the mercury solid was fun.
A more interesting link about the hazards of dry ice in a plastic bottle with water added can be found at the Darwin Award website. It’s listed under personal accounts and is one of the top 20 stories when you open the personal accounts link on the main page. Titled “Scrambled Eggs” I’m C&Ping here the full entry:
"When I was seventeen, I pruned the future of my own family tree.
"(2002) Some friends and I had heard that you can make a plastic two-liter bottle explode by using dry ice and water to create pressure inside the capped bottle. We gathered up as many plastic soda bottles as we could, obtained dry ice from the icehouse, and planned targets for this particular brand of mayhem.
"After the first “dry ice bomb” had gone off, we were left disappointed with the length of time it took to actually blow. Our first idea was to use a smaller bottle, but a one-liter bottle only created a weaker, but still painfully delayed, explosion. The second idea was to use warm water to drive a faster reaction with the dry ice. This created a more reasonable time for us to wait until the sweet satisfaction of being a successful teenage vandal came to fruition.
"Now we became greedy. If warm water made it better, then hot water must make it even better still! Yours truly was the one to try it. I added ice, poured scalding hot water into the bottle, and capped the “bomb”. I recall an immediate ringing in my ears, and blood, and plastic shards. The hospital was only a mile away, but it seemed like a light year.
"At the hospital, I was rushed in and quickly assessed. Due to the way I had been cradling the bottle, my groin and thighs took most of the damage from plastic shrapnel. At the age of thirty, I have many scars to remind me of my teenage stupidity, but none as monumental as my pair of silicone testes! "