Can someone please explain why this happens?

Question

Ok... so the other day I went to my fridge to get a bottled water (aquafina) and it was in the bottom of my refridgerator. So i reached down to pick it up and it wasn't frozen but while I walked away with it it began to freeze. Why in the world does this happen because it defies my knowledge of physics.... o and also onetime I did the same thing except I poured one of those flavor packets into it and it began to freeze. anyways can someone explain why this happens

Answer 1

Could it be that the outside temperature is lower than the temperature inside the fridge?

Answer 2

When you took the bottle out, it didn't freeze. Rather, since the bottle was colder than room temperature the moisture in the air around the bottle condensed and formed a frost coating. Ask any bar tender who chills bear glasses.

I believe the other case is similar to "seeding" a cloud. If the liquid is cold enough, but not at the freezing point, the fine particles of the powder provided a nucleus around which ice crystals can form.  

Answer 3

Listen to the professor (GetFreducated).  What he says is dead on.  I'm sorry to say that "Over" is wrong.  Bottled items (near freezing) and under pressure will freeze when opened, of course.  That is not what you saw...you saw that a supercooled liquid will freeze when "disturbed".  

A supersaturated solution will look clear but if you tap it with a stirring rod...POOF...out rains the extra precipitate.

Answer 4

The water was supercooled.  It was a liquid with a temperature below freezing.  The agitation of the water (by addition of the powder) gave the ice a place to form.

-Fred

You can superheat water in a microwave and then add a tea bag.  You should not do this because the water will "explode" into a boiling mass.

If you supercool a beer in the freezer and open it while it is a liquid, the additional energy released by opening the bottle will cause the entire bottle to freeze in a fraction of a second.  It's pretty cool stuff (no pun intended).