Put a cup of boiling water and a cup of room temperature in the refrigerator, why does the boiling w

This question is not very accurate, for example, what kind of container is the water, open, or sealed; Materials that do not easily conduct heat or materials that conduct heat easily; The height of the water in the container (full glass, half a cup) and so on, I think it all affects the result. I think the original intention of this questioner should be: which one will freeze first; The purpose of this question should be to illustrate that water vapor can freeze quickly below freezing.

If this is the case, it should be boiling water, because the water vapor of boiling water is much more than the room temperature, and if the experiment is carried out, it should be that the mouth of the boiling water cup will freeze, and the water temperature at this time will still be very high, because the glass is not easy to conduct heat, which will cause the temperature of the glass mouth to be extremely low, and the water vapor will condense and freeze as a result. 0

Physically, there are four mechanisms of cooling: radiation, conduction, vaporization, and convection.

It would be even more revealing if the process of hot and cold water freezing was described and the causes of it were analyzed

A cup containing cold water with an initial temperature of 4 freezes for a long time, and the water in the cup expands in volume due to the drop in temperature, and the density becomes smaller, and it gathers on the surface. Therefore, the water freezes first at the surface, followed by the bottom and the periphery, which also acts as a constraint or inhibition on further freezing.

The cup containing the initial temperature of 100 hot water has a relatively small freezing time, and the phenomenon seen is that the ice layer on the surface can not be connected into an ice sheet, and the phenomenon of "ice shell" formation cannot be seen, so the hot water freezes first.

There are two possibilities for this problem:

1.When the temperature of the cup of hot water is not very high, about 40 to 50 degrees Celsius, it is obvious that the cold water freezes first.

2.When this is a cup of boiling water, there is a good chance that you will see the hot water freeze first. The process of freezing in the refrigerator is the process of accelerating the loss of heat.

In physics, in general, a substance needs to release heat when it is converted from a liquid state to a solid state, and a cup of hot water has significantly more heat than cold water, so it obviously needs to lose more heat, and the cooling time required will be longer. But it's not the same if it's boiling water. After the water is boiled, the dissolved oxygen and other impurities in it will volatilize, then this glass of water is equivalent to being purified (water in nature has impurities), and the freezing point of pure substances will change, which is different from water in a pure natural state, so you may see the phenomenon that the hot water freezes first.

At first glance, our first impression is that of course the cold water freezes fast. But that's not the case. If you put two cups of water of equal weight in the refrigerator, one cold and one hot, they will start to lose heat in the refrigerator at the same time.