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Author Topic: Would A Single Ice Cube Freeze An Almost Very Cold Glass Of Water ?  (Read 3956 times)

Offline neilep

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Dear Iceologists,

As a sheepy I of course luff ice. Ice is my all time favourite thing that is made when ewe freeze water.

Look here's some !

Some ice hanging about earlier today

Oh my !..that is some well sexi ice happenning there !..if I was a boi ice and that was a bunch of girl ice I would be well happy !

Ice is well kewl because it helps keep drinks cold..look here's a glass of water

.....the sexi wanton cum-hither thing is a real temptress and is really asking to be filled with ice !

What would happen though if my glass of water was literally just a soupçon of a degree from being turned into ice and I then added a single ice cube ?... Would the ice cube start the process of bringing the temperature down within the glass so that it turns into a glass popsicle ?

Whajafink ?

Hush & shmishes

mwah mwah mwah !!

I Luff Eau



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Old fashioned language coming up - but it explains things, I think. (Back to School for this one)
It takes about 80 calories to melt 1g of ice at 1degree Celcius or you need to remove 80 calories for it to freeze. That's what is / was called the Latent Heat of Fusion.
Those 80 calories could raise / lower the temperature of 1 g of water by 80 degrees.

So, if you could imagine a 1g cube of ice, frozen to -80 C. It could freeze 1g of water and leave 2g of ice (at 0C). This assumes there is no other heat coming in or out.

A 10g block of ice at -8C would freeze 1g of water - and so on.
 The energy involved in changes of state is huge (Latent Heat)  compared with the heat involved in changes of temperature (Quaintly referrd to as 'Sensible Heat').
There's about 70 times as much energy involved in boiling / condensing water, compared with freezing - which is why the steam from a kettle hurts so much and Cappuccino machines are so magic at warming the milk up.
Latent heat is why ice works so well at cooling your Martini. (Shaken not stirred is best because it's quicker and you can take off  the surplus ice with the cocktail shaker without diluting the drink too much).
« Last Edit: 03/08/2009 14:44:05 by sophiecentaur »

Offline Karen W.

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So Calories melt ice? I*s that because calories are full of energy and energy is burned and produces heat because of its energizing properties... I never associated a calorie to ice in so far as it melting ice?

How is that please? I am not sure I understand?

Offline sveur

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A calorie IS energy. 1 calorie = 4.18400 joules

Offline sveur

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And the calories we talk about in food and such, are actually kilocalories, a thousand calories. newbielink: [nonactive]

Offline John Chapman

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So, if you could imagine a 1g cube of ice, frozen to -80 C ...... A 10g block of ice at -8C .....

Talking of "back to school", I thought that under normal conditions water ice always had a temperature of 0C. I was always told that in winter snow actually insulates the ground stopping sub-zero temperatures from killing the over-wintering plants and small animals. Isn't that how igloos and ice caves work, creating a lower limit to the ambient temperature? Don't chest freezers become inefficient if allowed to frost up badly because once fully encased by ice the temperature inside will not fall below 0C?

Have I somehow made an assumption as a kid which over the years became reinforced until I believed it to be a fact?


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You can cool a block of ice as cold as you like. Ice, in equilibrium with water (i.e. floating in it, having attained a steady temperature, will stay at 0C but that doesn't mean you can't take the temperature down further, once all the Latent Heat has been taken away and it's all frozen. Snow is a fairly good insulator (so is water, of course- if you can stop it from convecting heat about the place*) which is what 'people say'. A sleeping bag would have the same effect; even when at -20C, it will reduce heat flow effectively.

The reason that chest freezers don't work efficiently when iced up will be because the ice insulates the food from the cooling panel and the unit has to run more in order to keep the compartment at the required temperature. The refrig unit has to 'try harder' to pump the same amount of heat out of the compartment by having the cooling panel at an even lower temperature than it would normally be.
Right fact - wrong reason. Same as a lot of things our Grannies told us.

If you burn some Olive oil, rather than eating it, the energy released can heat water instead of adding to your girth! SO BURN ALL CHOCOLATE.

*Great little demo: Take a test tube full of water and hold the bottom. Hold the top in a bunsen flame and it will boil very quickly but the water in the bottom stays cool enough to hold for ages.  (the water is an insulator) Holding it and heating it the other way round, you need to let go pretty soon because convection spreads the heat all over v. quickly.

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