Naked Science Forum

General Science => General Science => Topic started by: Aaron Zimmerman on 27/04/2008 13:07:07

Title: What is it we see in dry ice?
Post by: Aaron Zimmerman on 27/04/2008 13:07:07

Aaron Zimmerman  asked the Naked Scientists:
Hi my name is Aaron, I am a student attending the University of Wisconsin in the U.S.  

My question is about dry ice, most people are familiar with it's smoky effects.  As I understand it, dry ice is a good example of a sublimation, of a solid going directly to a gas.  My question is if the solid white carbon dioxide is changing directly into a gas then why can I see the smoke, since carbon dioxide is colorless?  Is is water condensing out of the air, or small bits of particle picked up in the currents formed by sublimation?  

Thanks for any help, love your show, just caught up on 3 years of backlogs in the last three months!  

Keep it coming and keep it naked!
   
Aaron Zimmerman
What do you think?

Title: What is it we see in dry ice?
Post by: Madidus_Scientia on 27/04/2008 15:53:41

Yes, it is just the fog from water condensing from the air in the colder carbon-dioxide gas

Title: What is it we see in dry ice?
Post by: NeilT on 28/04/2008 22:26:25

Whatever you do, don't sit on it!

http://news.bbc.co.uk/nolpda/ukfs_news/hi/newsid_3579000/3579331.stm (http://news.bbc.co.uk/nolpda/ukfs_news/hi/newsid_3579000/3579331.stm)

Title: What is it we see in dry ice?
Post by: Make it Lady on 28/04/2008 22:50:16

I see the future. I see a tall, dark, handsome stranger. Sorry, think you got your answer and couldn't resist.

Title: What is it we see in dry ice?
Post by: chris on 30/04/2008 08:46:42

The lady in the picture seems to have quite an icy look on her face, if I may say so.

Chris