Which freezes faster Hot or cold water?

In summary, the speaker needs to determine whether hot or cold water freezes faster for a class assignment. They are looking for ideas and explanations, but do not want to actually conduct an experiment. The other person suggests doing an experiment, as physics is an experimental science.
  • #1
ShelbyMcD
13
0
So this isn't homework, but it is for a class and I don't know how to go about this... I have to figure out if hot or cold water freezes faster. Any ideas?
 
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  • #2
Why don't you do the experiment?
 
  • #3
Because I have to write about it and think about it, not do a lab on it. I just need some ideas and explanations.
 
  • #4
ShelbyMcD said:
Because I have to write about it and think about it, not do a lab on it. I just need some ideas and explanations.

Then it is homework. Please repost in homework with an attempt.

But in any case, it never hurts doing an experiment. After all, physics is an experimental science. The theory and explanations can be very nice and pretty, but it's the experiment that decides all.
 
  • #5


I can provide an evidence-based answer to this question. The phenomenon of one liquid freezing faster than another is known as the Mpemba effect. It has been observed that under certain conditions, hot water can indeed freeze faster than cold water.

The Mpemba effect was first described by Aristotle in the 4th century BC. However, it was not until the 20th century that scientists began to study and understand this phenomenon. Several factors can influence the freezing rate of liquids, including temperature, container material, and impurities.

One of the key factors that contribute to the Mpemba effect is the presence of dissolved gases in water. When water is heated, it drives out dissolved gases, leading to a decrease in the amount of dissolved gas in the liquid. This decrease in dissolved gas can create a nucleation site, which is a point where ice crystals can begin to form. This can accelerate the freezing process.

Additionally, hot water has a lower viscosity than cold water, meaning that it flows more easily. This can also contribute to the formation of nucleation sites and accelerate the freezing process.

However, it is essential to note that the Mpemba effect is not always observed and is highly dependent on the specific conditions of the experiment. Factors such as the starting temperatures of the hot and cold water, the amount of impurities present, and the type of container used can all affect the freezing rate.

In conclusion, while hot water can freeze faster than cold water under certain conditions, it is not a universal phenomenon. As a scientist, it is crucial to carefully control and consider all variables when conducting experiments to accurately determine the freezing rate of liquids.
 

1. What is the Mpemba effect?

The Mpemba effect is the phenomenon where hot water freezes faster than cold water under certain conditions. It is named after Erasto Mpemba, a Tanzanian student who first reported this observation in the 1960s.

2. Why does hot water freeze faster than cold water?

The exact reason for the Mpemba effect is still debated by scientists. Some theories suggest that hot water has less dissolved gases, which allows it to freeze more quickly. Others propose that the evaporation of hot water during the cooling process can cause it to lose more heat, thus freezing faster.

3. Does hot water always freeze faster than cold water?

No, the Mpemba effect is not always observed. It depends on various factors such as the initial temperature of the water, the container it is frozen in, and the surrounding environment. In some cases, cold water may freeze faster than hot water.

4. How does the Mpemba effect impact daily life?

The Mpemba effect has practical applications in industries such as food preservation and ice cream production. It is also important for understanding the physics of water and how it behaves under different conditions.

5. Are there any other substances that exhibit the Mpemba effect?

Yes, the Mpemba effect has been observed in other liquids such as alcohol, milk, and honey. However, the conditions for it to occur may vary depending on the substance.

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