28 Dec 07
Originally posted by wolfgang59Another possibility is that since hot water expands, a volume of cold water will actually contain more water than an equal volume of hot water. Thus it may need less energy removed to freeze.
Any impurities in water will lower the temperature at which it freezes (hence polar seas are sub-zero) and its why we put salt on our paths.
Hard tap-water contains lots of calcium salts (amongst others) and this will affect the freezing point. Boling the water first will have no effect.
Some tap-water has 'temporary' hardness cause by bicarbonate m ...[text shortened]... xperiment maybe to COMPARE water from different sources regarding the boiling/freezing thing.
28 Dec 07
Originally posted by AThousandYoung"... a volume of cold water will actually contain more water than an equal volume of hot water ..."
Another possibility is that since hot water expands, a volume of cold water will actually contain more water than an equal volume of hot water. Thus it may need less energy removed to freeze.
There is exactly the same mass of water. Only density is less. Energy needed is defined by mass.
28 Dec 07
Originally posted by Sam The ShamThe water is allowed to cool. Both the previously boiled water and non-boiled water go into the fridge at the same time. Same density. Same mass.
Actually the myth is that water that has just been brought to a full boil, then allowed to cool, will freeze faster than water at the same temperature that hasn't. And I don't know if it's true or not.
The phenomenon is purely to do with relative purities. (pun intended)
28 Dec 07
Originally posted by FabianFnasGRANNY is performing this experiment as you sit and ponder. So far, nothing has reached room temp. I assure you that iam using the same quility controls that i used when i worked at Bell Labs.
How much doesl the relative volume change for each centigrade colder at, say, 2 degree Celsius?
Granny
29 Dec 07
Originally posted by smw6869Both samples are at room temp (60degrees)
GRANNY is performing this experiment as you sit and ponder. So far, nothing has reached room temp. I assure you that iam using the same quility controls that i used when i worked at Bell Labs.
Granny
Placed in freezer, next to each other. Time: 5:27.
Time: 6:40 - cold water- some ice crystals on top.
hot water - no ice crystals.
GRANNY
29 Dec 07
Originally posted by smw6869Time: 8:00 - Cold water- half frozen
Both samples are at room temp (60degrees)
Placed in freezer, next to each other. Time: 5:27.
Time: 6:40 - cold water- some ice crystals on top.
hot water - no ice crystals.
GRANNY
Hot water - crystals on top
Why is this taking so long? What's wrong with my freezer?
Hello. Does anyone care? Cokie, where are you?
Granny.
29 Dec 07
Originally posted by smw6869Final results:
Time: 8:00 - Cold water- half frozen
Hot water - crystals on top
Why is this taking so long? What's wrong with my freezer?
Hello. Does anyone care? Cokie, where are you?
Granny.
Time: 8:37 -- cold water frozen solid
- Hot water - half frozen
Granny
29 Dec 07
Originally posted by FabianFnasAt that temperature the volume begins to increase as it gets colder because the structure of ice requires expansion of the water as it freezes. However we're not talking about cold and colder water. We're discussing hot vs cold water; cold as in cold from the tap, not cold from the freezer.
How much doesl the relative volume change for each centigrade colder at, say, 2 degree Celsius?
