Freeze

What freezes faster hot water, cold water, why?

Originally posted by KellyJay
What freezes faster hot water, cold water, why?

Ice boils faster than room temp. water..uses less energy...

Originally posted by woadman
Ice boils faster than room temp. water..uses less energy...

Take a look at this:
http://www.school-for-champions.com/science/heat_ice_steam.htm#.VPtCZfnF-sQ

Originally posted by KellyJay
What freezes faster hot water, cold water, why?

Cold water freezes faster. Why? Before hot water can freeze it first has to become cold water.

Originally posted by Soothfast
Cold water freezes faster. Why? Before hot water can freeze it first has to become cold water.

I made that mistake over in Spirituality. There's something called the Mpemba effect, first noticed by a Tanzanian school student called Erasto Mpemba, there are various ideas as to why this should be so. The latest theory is that it is something to do with hydrogen bonds. The effect is not consistent. There is no doubt about it, water is weird stuff.

http://en.wikipedia.org/wiki/Mpemba_effect

Originally posted by KellyJay
What freezes faster hot water, cold water, why?

You cannot freeze hot water at all. Because when water freezes it is not longer hot.

Not in normal atmosphere it doesn't.

Originally posted by DeepThought
I made that mistake over in Spirituality. There's something called the Mpemba effect, first noticed by a Tanzanian school student called Erasto Mpemba, there are various ideas as to why this should be so. The latest theory is that it is something to do with hydrogen bonds. The effect is not consistent. There is no doubt about it, water is weird stuff.

http://en.wikipedia.org/wiki/Mpemba_effect

"The Mpemba Effect, named after Erasto Mpemba, is the observation that, in some circumstances".

Quite.

In general, though, cold water freezes faster than hot.