Re: Why does ice form in a bottle of club soda the moment it is opened?

Benny,

This is a very interesting observation.  Your research and theory were 
very good.  It explains why the club soda (water and CO2) "changed state" 
from liquid to solid but leaves us with the problem of the soda.

After visiting the coca-cola website,
 http://www.cocacola.com

I followed their "ask coca cola" link and typed in "freezing point of 
coke" and pressed the "talk" button.  I received the following answer:

"We do not monitor the exact freezing temperatures of each of our 
products. However, our diet products freeze at a temperature similar to 
water, 32 degrees. Coca-Cola classic freezes at a slightly lower 
temperature, about 30 degrees. The pressure in an unopened bottle or can 
will cause the freezing point to be even lower. All diet beverages will 
freeze before their sugar counterparts. Sugars lower the freezing point of 
liquids. This means that the temperature must get lower than the normal 
freezing point of water before it freezes."

While the pressure decrease (opening the bottle) may have caused the ice 
to form by raising the freezing point in your club soda, the freezing 
point of the sugared soda would generally be lower than that of the water, 
and that may be why the soda did not freeze under similiar circumstances.

If you decide to explore this with further experimentation, select 
containers that are similiar (if not identical) for such comparisons.  
There are too many differences between glass, plastic, and aluminum under 
such conditions (for example their 'thermal conductivity' is different) to 
allow direct comparisons.  It is very important when a scientist conducts 
comparisons to make sure they are comparing "apples with apples" as the 
saying goes.

Good luck!

Sincerely,
Steven Miller
smiller@kahuna.sdsu.edu
Bachelor of Science, Mechanical Engineering
San Diego State University (Alumnus)