Both Aristotle and Francis Bean believed this to be true. It has been proven fact in several different experiments by many different scientists. You gave a good answer, and certainly helped out Dara, but I just wanted to make sure she got all her facts straight. Mackenzie- Thanks for your note. You're right to remind us that the common-sense result isn't always right. Sometimes the hot water freezes faster. I would be a little more cautious than you about authority, however. Aristotle made many mistakes, even on simple questions like how many teeth women have.
Francis Bacon is that who you mean? My own attempts to repeat this experiment have flopped so far. I always forget to look at the glasses until they're both frozen. You might try it yourself, using metal cups so they don't break, and being sure to put the same amount of water in each. Also, try it a few times switching the positions of the hot and cold cups, since freezers don't cool evenly.
The most careful discussions of the subject e. I think Tamara has a good discussion on this site, under the name 'Mpemba effect', named after a high school student who had the courage to believe his observations rather than his teachers.
Mike W. Hot water does not freeze faster than cold water. That idea is ridiculous. It can be misconstrued as such when you look at it without a mind towards physics and chemistry.
When a liquid is cooled, it may pass the freezing point and not appear to freeze. This is due simply to the fact that the molecules need additional energy or a solid to begin the crystallization process. If you put boiling water in the freezer along with cold water, the cold water would reach the freezing point of 0 C much more quickly, but it does not make the transition to ice until a force acts upon it. If you rap the glass you will see the liquid freeze in front of your eyes.
The boiling water would not even have reached the previous temperature of the cold water. In conclusion, with both liquids under constant pressure, there is no way for hot or boiling water to "freeze" first. Your argument makes a great deal of sense, but subtle complications in the real world can give strange results. Here's an example. Let's say that you set the water in a glass in a freezer with a lot of frost.
The hot water may melt the frost, and then make excellent thermal contact with the cold shelf. The cold water may sit on top of the frost in poor thermal contact. Then the initially hot water could cool more quickly and end up freezing first. In some cases it's necessary to actually do experiments to find out how things act. Can someone answer my question??
Dear Kavi, The actual time depends on may factors: thermal contact and quantity of cocoa, beginning temperatures of the freezer and coca, composition of the cocoa, etc.
The best answer is for you to do the experiment and find out for yourself. Try it several times varying one or another parameter.
Keep a record and see if you can figure out a trend. Let us know what you find. Can someone provide an answer on how long a specif volume of water will take to freeze at a typical residential freezer temp, i. This sort of problem is unanswerable because it depends on too many variables that we don't know the values of.
At best one can give scaling laws, for example twice the heat transfer rate will halve the freezing time or twice the volume, at the same transfer rate, will double the time. The freezing time depends on: the air circulation rate, the surface and shape of the container, the amount of contact area, etc. The best way to answer this question is to do some experiments and vary some of the parameters.
Eventually you will get some empirical idea of what's going on. Rate and time are being confused. Though related they are not the same thing. Hot water is often used because it lacks the dissolved air which makes the ice look cloudy.
Ice sculptures can be crystal clear like glass if the hot water is super cooled to freeze the water before much air gets caught in the water.
A Computer is usually doing the sampling automatically and graphing the results in a 2d graph showing the temp reading on the y axis and the time frame on the x axis. So you see water go from C to 1C in a short period of time, then it takes a much longer period of time compared to the C to 1C to go from 1C to 0C. Thus, the misunderstanding is that hot water freezes 'faster' than cold water. The same can be said about boiling water.
Maybe a more real world scenario is in order for clarification. Bob is standing at the beginning of a meter dash. Walter is standing 1 meter away from the end of the meter dash finish line.
The whistle blows! Bob is off to a speedy start traveling at 10 meters per second. Walter, being 1 meter from the end took his sweet time traveling at at only 1 meter per second and crossed the finish line 11 seconds before Bob.
Who was faster? Bob was faster! Who finished in the least amount of time? Walter, because he finished in 1 second. To properly calculate the time it would take to freeze a substance from point x to point y As many posts before said there is not enough information given.
Glasses are typically cylindrical in shape. Walter- I should defer to your advanced age, but I see no evidence that anyone was confusing time and rate. These messy practical heat flow problems cannot reliably be reduced to your simple equations.
Here's some reasons why hot water could actually freeze sooner, surprising as that is. There's a burst of initial evaporation. Since a glass of frozen water is not going to help you entertain your guests at a party and even less so a lake or a pond! Mostly, a standard plastic ice tray that holds 12 cubes filled with room temperature water will take around 3 to 4 hours to freeze in a home freezer.
Of course, you get ice trays in various sizes and made out of different materials, and all of this will affect the water freezing point. Three factors will affect the time it takes to make ice cubes:. If you have an ice tray with an unusual size, it will affect the freezing time.
So, watch out for those cute ice cube trays that produce ice in different shapes or the tiny ice cubes that are great for crushed ice or decorative drinks. The bigger the block, the longer it will take for the water to freeze. The surface area affects the time it takes for your ice cubes to be ready to be used. Water freezes from the outside in. This means that ice trays with air space between each cube freeze quicker than a tray with dividers.
We've learned that water freezes at 32 degrees Fahrenheit 0 degrees Celsius. But did you know that home freezers don't all run at the same air temperature? Although most run at 0 degrees Fahrenheit, which is optimal, this can vary. Every time you open your freezer or put food in that's at room temperature, the temperature in the freezer increases.
How quickly water freezes depends on various environmental factors. However, the ice tray's material generally does not affect how long it takes for the water to freeze and turn into ice cubes. Whether your ice cube tray is plastic or silicone, it should not make a difference. However, there are exceptions to this rule.
If you have an unusual ice tray designed to make very small ice cubes , these will freeze faster than large blocks of ice. The surface area of the ice will also affect freezing time, since ice begins to freeze from the outside in. This means that an ice tray that has air space between each cube will freeze faster than one that merely has dividers.
Second, the air temperature of your freezer matters. Most home freezers are set at 0 degrees Fahrenheit, which is optimal. For starters, make sure that you keep your freezer at the recommended temperature and keep it closed as much as possible — that means no checking on it for at least three hours.
You can also try using a stainless steel ice cube tray instead of a plastic or silicone one. Metal is a very poor insulator, so the water will cool down more quickly. This method relies on the Mpemba effect to get your ice to freeze faster than it would if you used cold water in your ice trays. The Mpemba effect is a bit of a paradox. Mpemba noticed that when he made ice cream with hot milk, it froze faster than chilled milk. Mpemba then tried experiments using warm water to make ice, and scientists replicated them.
They discovered that, in many cases, warmer water does freeze faster than cool water. Hot water freezes faster than cold water this is called Mpemba Effect.
Has anyone ever wondered whether the water hardens equally quickly in different surroundings? Is water freezing time equal for the fridge frosting camera and the open-air pool like a lake, for instance? In fact, the outcome differentiates. Since in the frosting camera, the liquid is affected by frost under the stable conditions, the open-air pools are affected by the constantly changing weather conditions and other fluctuations. So, what temperature does water freeze in Fahrenheit?
One two hundred milliliters tank of liquid will require nearly three hours before hardening completely. Using a powerful freezer, one gallon will most likely freeze after staying there overnight.
However, other conditions must be also considered. From half an hour to two hours in general. Everything hangs upon the capacity of the bottle and the temperature in the freezer. Respectively, one can calculate the freezing time for a three-liter bottle and further up to as a voluminous tank as you need.
But be aware that these numbers are only valid for the ordinary home frosting cameras! Colder freezers will make the liquid solidify faster hanging upon the temperature rate inside them. From three to four hours. Since the majority of the ice-making trays that we use have a dozen of separate sections, they will freeze in a usual home frosting camera in about 3 hours.
If you use a nonstandard tray — about 4 hours. A conventional tray meant for dozen of ice pieces will become completely frozen in four hours at most.
Nevertheless, we would recommend everyone to consider certain nuances regarding freezing. As everyone knows, the water turns into ice when it reaches the mark of zero degrees Celsius. Definitely, different kinds of liquids harden at a different temperature rate and under different conditions.
Everything hangs upon the specifics of the structure of each particular liquid. Now the secret is revealed! So whenever some liquid needs to be transformed into ice, you will know for sure how much time to wait until the desired result will be received.
Have you ever thought of those mysterious and unexplained traits of such a common liquid as water? As you can see, H2O is indeed a tricky and mysterious substance that still has a lot of secrets that our science is only about to discover! Freezing water can hardly be called something that common people are interested in. Nevertheless, when we need to chill something liquid at home, this issue becomes a true point of concern!
That is why so many of us have lots of related questions regarding different issues connected with freezing water and other liquids. To help you out to answer those questions and to make it simpler to sort out the facts, we have collected the most common questions asked by people, each with the detailed answer.
Quite a widespread belief exists that the solidifying period needed for water in an ice cube form to harden completely hangs upon the number of sections this form consists of. In point of fact, what really matters is the amount of substance in each section.
No matter how many sections the tray has, the average period needed until the substance freezes is usually three to four hours. Nevertheless, if your particular tray has deeper or shallower sections, the amount of time might be less extended. Sometimes knowing how fast ice forms can be even life-saving, especially when it comes to wild nature aqua, for instance, lakes or rivers. In such a case, the answer hangs upon the size of the basin, depth, plus the air temperature around.
For this reason, a large lake freezes after at least a week. The science researches show that normally an ice film on the surface of such a basin grows for 1 inch per each fifteen freezing degree days in a twenty-four hours period. Sometimes it is useful to know how soon we can get our ice cubes, or some ice-cold water, right? Well, the answer to this inquiry hangs upon the amount of liquid we chill.
Primarily, if we place a ml flask with aqua to the frosting camera, it will change into ice after approximately three hours. In contrast, the content of an ice tray will harden after the four hours of contact with frost.
Basically, the answer says: the more sizeable the tank is the longer it needs to shapeshift into ice. However, the level of heat the liquid had before it was placed to the frosting camera also matters. As everyone knows, water freezes best at 32 F. So normally, a small portion of the aqua freezes after three to four hours spent in the frosting camera of the fridge.
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