why do hot water freeze quicker than cold water?

Answer 1

cold water would take less time to freeze than hot water.
The only difference between the two will be the temperature gradient. Hot water will have a higher rate of heat loss.

Answer 2

When you put hot water in the freezer, the thermostat kicks in and makes the freezer colder. Also, hotter molecules evaporate more easily, leaving the colder molecules behind- that is called evaporative cooling. An interesting experiment would be to weigh hot water and cold water and freeze each, then weigh them again- see if there is a difference.

Answer 3

Hot water is in a more gaseous state than cold water and under the right conditions a sort of flash-freezing effect accelerates what would other wise have been a more glacial process (pun intended).

Answer 4

Hot water can in fact freeze faster than cold water for a wide range of experimental conditions. This phenomenon is extremely counter- intuitive, and surprising even to most scientists, but it is in fact real. It has been seen and studied in numerous experiments. While this phenomenon has been known for centuries, and was described by Aristotle, Bacon, and Descartes, it was not introduced to the modern scientific community until 1969, by a Tanzanian high school student named Mpemba. Both the early scientific history of this effect, and the story of Mpemba's rediscovery of it, are interesting in their own right -- Mpemba's story in particular provides a dramatic parable against making snap judgements about what is impossible. "Always Look outsideof the box"

Answer 5

Yes it do freezes quicker than the cold water...
...bcoz in cold water, the water molecules are already close to each other... while in hot water they are far apart...

Answer 6

Only with hard water does that happen.

Hard water refers to dissolved ions. Some of them precipitate at hot temperatures.

They can inhibit water from freezing, so precipitating them out makes the water freeze faster.

However, this only happens with the right water!

Answer 7

It doesn't.

Ignoring completely things about molecular energy, hot water has to be cold first before it can be frozen. Since cold water is already cold, it's one step closer to the end goal.

Answer 8

it's not true. Water freezes at the same rate regardless of its orignial temperature, so therefore, the same volume of cold water would freeze faster than the same volume of hot water.

Answer 9

it doesn't. hot water naturally has more energy than cold water, and cold water would take faster to freeze than hot water.

Answer 10

it doesnt. you've actually got it completely backwards. cold water has less energy, so it takes less overall energy loss to make it freeze. hot water will take far longer to freese than cold water.