Iced Tea
Science brain teasers require understanding of the physical or biological world and the laws that govern it.
One hot afternoon two friends were out relaxing on the back porch.
"Would you like some iced tea?" one man asked his friend.
"Oh yes as long as it is good and cold."
The host then brought his friend a large glass of iced tea and dropped two small ice cubes in it.
His friend took a sip and remarked, "It's not very cold."
"Give it a minute," the host said.
The iced tea then appeared to start boiling. After a minute or so the ice melted, the boiling stopped, and the glass was ice cold.
The man took a sip and thanked his friend for the very cool drink.
So what made the iced tea cool in this unusual way ?
HintThink of the boiling and the ice cubes.
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Answer
The man put dry ice cubes in his friend's drink. This gave it the appearance of boiling as the ice melted. This also super-cooled the drink in a short time.
It's a great holiday party trick. Just don't swallow the ice - very dangerous.
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Comments
speedyg1000 
Dec 22, 2002
| dry ice in a drink? someone told me there were chemicals in dry ice but i guess not. good teaser! |
MrIxolite   
Dec 22, 2002
| I thought dry ice was just frozen Carbon dioxide? |
od-1   
Dec 24, 2002
| Dry ice is just frozen carbon dioxide
and the bubbles its creates are the same as when you carbonate a drink.Thus giving driks that carbonated taste.just don`t swallow the cubes or even let then touch you lips if you do this dry ice is cold enough to cause frost bite
with in a few seconds |
doggyxp  
Dec 26, 2002
| At first I though it had something to do with the molecules diffusing through the tea, but why would that create a boiling look? I liked your answer. |
Deucex2  
Jan 09, 2003
| It's worth noting that dry ice would quickly cool the drink, not supercool it. Supercooling is a relatively rare phenomenon where a liquid stays liquid below its freezing point. Once something disturbs it (like shaking the vessel) it freezes instantly. I saw it happen in a lab one time and it was quite amazing. The counterpart is superheating, where liquids don't boil despite being quite hotter than their boiling point. This commonly happens in microwave ovens- watch out when you reheat your coffee! |
golfer132003
Feb 10, 2003
| Like said before handle this stuff with care and wear gloves. This stuff can cause serious damage. Also like said before smarter and safer to use ice. |
(user deleted)
Mar 14, 2003
| C'mon, you don't need to be that careful with this stuff. Don't swallow it, for sure - but we always used dry ice as a party trick in this way: keep a very small piece in your mouth, and move it around quickly with your tongue so it will not burn (freeze) you - keep your mouth closed during this time. After a few seconds exhale - the effect is that a lot of CO2 (whitish in color) will rush out of your mouth, making it look like you are smoking or that your breath is steaming. |
collie07652 
Oct 24, 2004
| I got that one right away
|
I_am_the_0mega
Jan 03, 2005
| Errr... if we're talking standard-sized ice cubes, wouldn't that not just freeze the water inside the glass (and possibly shatter it from the rapid cooling), but also, assuming it didn't shatter, "fuse" the glass to his hand??? |
I_am_the_0mega
Jan 03, 2005
| Oh, right.. i forgot. When drank, LN2 will absolutely destroy your tissue on its way down.. though, it probably won't make it, since it will solidify....
I mean seriously, when LN2 is used for cooling computers, you can run a 3GHz P4 at 5GHz+.... and where temps would be impossibly high (like... oh, say 180ºF..) they're in the negatives.. |
od-1   
Jan 03, 2005
| Dry ice is not liquid nitrogen, but frozen
carbondioxide . Big difference and this trick really works, I've done it my self many times. |
knbrain  
Jan 03, 2005
| That was easy... |
trailme247
Jan 03, 2005
| That was a good one! I had to let the whole family in on that one!
THAT WAS TO COOL! |
IMCUL4E   
Jan 03, 2005
| knew it right away. Almost too easy |
chessnut418
Jan 03, 2005
| way too easy |
taelsey
Jan 03, 2005
| This one was too easy! |
punkin  
Jan 03, 2005
| that was cool, if i didn't know my science you could had got me!!!! |
punkin  
Jan 03, 2005
| |
mivich 
Jan 03, 2005
| that one was good.ishowed it to my family |
this_is_just_me
Jan 03, 2005
| that is very easy easy to answer.good one though!!!!!! |
Jonesy
Jan 04, 2005
| way easy! But very fun too! |
(user deleted)
Jan 04, 2005
| an't dty ice just carbon monoxide (cant spell) and an't that deadly?? |
tiptoes007berbs 
Jan 24, 2005
| I got this one right away although, I\'ve been to a few Halloween parties in my day..... the stuff looks good in a witches kettle aswell |
vbguy101   
Sep 02, 2006
| DUHHHHHHHHHHHH!
The process of a solid passing directly to gas is sublimation. Oh, by the way, DO NOT, inhale the vapors. It's carbon dioxide and you could die of CO2 poisoning.  |
zroach
Jul 05, 2007
| This would not cool the iced tea quickly. In fact, using regular ice would cool the drink faster than dry ice. That is because the Ice takes a higher temperature to melt it takes more heat from the drink than Dry ice would. |
myhalcyondaze
Jun 03, 2008
| @vbguy101
You are correct in stating that the dry ice is sublimating. However, it is highly unlikely that you would be poisoned by dry ice (hypercapnia), assuming you are using a reasonable amount in a normal setting. Every time you exhale, you're exposing yourself to CO2, but there is enough oxygen available that it isn't an issue. You may be thinking of carbon monoxide (CO, not CO2) which is MUCH more toxic than carbon dioxide. Dry ice is NOT made of carbon monoxide (as mentioned by one commentor above). |
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