Forum Home
PC World Chat
 
Thread ID: 63635 2005-11-17 06:10:00 Fridge Temperatures EX-WESTY (221) PC World Chat
Post ID Timestamp Content User
405061 2005-11-17 06:10:00 There was recently an article re the temperature of NZ fridges and safe food storage temperatures. NZ Herald article (www.nzherald.co.nz)

Well I didn't have to adjust my fridge temperature at all cos I thought it was cold enough in fact.
This afternoon when I was in the kitchen there was a bang that came from inside the fridge and I opened the door to find the roof and walls dripping with coke from a can at the rear which had obviously frozen and then exploded.

As if the bang wasn't enough there is now a whining noise coming from the direction of the fridge but I have traced this to the wife. :D
EX-WESTY (221)
405062 2005-11-17 06:23:00 I thought only frigid wives made whining noises :D :D :D Shortcircuit (1666)
405063 2005-11-17 09:20:00 I was told by my Refrigeration instructor that only 3 things should be keep in fridges.

Beer,Water and Whiskey ( He was of Scottish Descent).

One question about the exploding coke. If it was frozen, how come it was dripping off the walls of the fridge? Have the the laws of physics been changed? Usually what happens is the coke will expand and split the can.

Jeff.
Jeff (1070)
405064 2005-11-17 09:37:00 The can was distorted at the top by the ice inside the can and it had formed a peak and blew a hole in the top rim of the can. The ring pull didn't give way at all. There was coke dripping off the roof of the fridge and the contents of the top shelf as well + a pool on the shelf and the can was still fizzing away releasing pressure.
I opened it up with a can opener a few minutes later and virtually all of the remaining contents were frozen.

Physics would say that volume increases when an liqiuid freezes, it just ran out of room before it could be completely frozen, hence the liqiud dripping. The CO2 would also have been undergoing a change as well.
EX-WESTY (221)
405065 2005-11-17 10:15:00 In Dunedin, we use fridges as heaters in the winter. :p

I love in the article "the highest recorded temperature was 18 degrees" - was it turned on?
gibler (49)
405066 2005-11-17 11:08:00 New Zealand's food poisoning rate is the highest in the developed world and no one knows why.

I blame telecom, The PC Company and the PM's driver.....
Metla (12)
405067 2005-11-17 18:42:00 The can was distorted at the top by the ice inside the can and it had formed a peak and blew a hole in the top rim of the can . The ring pull didn't give way at all . There was coke dripping off the roof of the fridge and the contents of the top shelf as well + a pool on the shelf and the can was still fizzing away releasing pressure .
I opened it up with a can opener a few minutes later and virtually all of the remaining contents were frozen .

Physics would say that volume increases when an liqiuid freezes, it just ran out of room before it could be completely frozen, hence the liqiud dripping . The CO2 would also have been undergoing a change as well .

you part here: "Physics would say that volume increases when an liqiuid freezes," :confused:

isn't quite accurate . Water is the sole liquid that expands when frozen keeping ice from forming and sinking to the lower levels of a lake and the results of that would be completely frozen lakes all the time .

Freezing another liquid (mercury, for instance) results in it's shrinking in volume at precise values letting it be used in thermometers etc . The same holds for other liquids . . they shrink . But water expands on both ends of the liquid condition . . heat it or freeze it and it expands proportionately to the temperatures involved .
SurferJoe46 (51)
405068 2005-11-18 03:05:00 . . .
Physics would say that volume increases when an liqiuid freezes, it just ran out of room before it could be completely frozen, hence the liqiud dripping . The CO2 would also have been undergoing a change as well .


Normally, the CO2 should be dissolved in the sugar, caramel, and phosphoric acid flavoured water . Perhaps what happened was that as the water froze, the CO2 was expelled, and reached a high enough pressure to pop the lid .

A standard technique to concentrate alcoholic beverages is to freeze them . The alcohol has a much lower freezing point, so is separated out . CO2 has an even lower FP .
Graham L (2)
405069 2005-11-18 09:43:00 Normally, the CO2 should be dissolved in the sugar, caramel, and phosphoric acid flavoured water.
CO2 disolves easily in water alone.


Perhaps what happened was that as the water froze, the CO2 was expelled, and reached a high enough pressure to pop the lid.

Guessing again?


A standard technique to concentrate alcoholic beverages is to freeze them. The alcohol has a much lower freezing point, so is separated out. CO2 has an even lower FP.

A standard? Damn, the beer must be bad in Christchurch ;)
Barnzy (6015)
405070 2005-11-19 02:12:00 Cans and bottles aren't filled to the top, so I don't think the (~4%) expansion can have caused the bursting .

The sugar and other ionic contaminants make a reduction in the solubility of CO2 in water . (Drinks with least sugar have most fizz) .

The solubility increases as the temperature decreases, but the solubility in ice is much lower . So CO2 will be expelled as the liquid freezes, and can reach a very high pressure . Once the can has popped, the CO2 will be expanding and cooling as it escapes, thus freezing any liquid remaining .

Have a look at Experiment 3 (a fair way down the page) in this
set of experiments (mattson . creighton . edu/SodaWater/SodaWater . html) based on Priestley's work which shows this happening . This
one (yarchive . net/chem/frozen_coke . html) looks interesting ,too .
Graham L (2)
1 2