# Thermodynamics and ice melting.

• Terp
In summary, the problem involves an open container with 0.585 kg of ice at -13.3*C being heated at a constant rate of 800 J/min. Using the equations Q=cm\Deltat and Q=mLf, the time it takes for the ice to start melting is 20.4 minutes and the time it takes for the temperature to rise above 0*C is 244 minutes. The total time it takes for the temperature to start rising is the sum of these two times.
Terp
[SOLVED] Thermodynamics and ice melting.

## Homework Statement

An open container holds ice of mass 0.585 kg at a temperature of -13.3 *C. The mass of the container can be ignored. Heat is supplied to the container at the constant rate of 800 J/min.

The specific heat of ice to is 2100 J/Kgand the heat of fusion for ice is 334x10^3 J/Kg.

## Homework Equations

Q=cm$$\Delta$$t
Q=mLf where Lf = fusion for ice

## The Attempt at a Solution

How much time t_melts passes before the ice starts to melt?
I got the answer to this to be 20.4 minutes and I know it's correct. I used Q=cm$$\Delta$$t= 1.63x10^4 J, where(c = 2100, m=.585, delta T = 13.3). I then used the rate of 800J/Min to get 20.4 min.

From the time when the heating begins, how much time t_rise does it take before the temperature begins to rise above 0 *C?

I'm absolutely stumped. It's probably very simple and right over my head. The hint for the problem had me find how much time it'd take to melt once it got to 0*C and I found that to be 244 minutes (using Q = mLf, then Q / 800J/min to get time), which is correct.

I feel like these two are the same question, since for the first one I'm finding the time it takes for the ice to start melting, which is at 0*c. Anybody have any clue? I've tried 20.4 min and 223.6 min and Mastering Physics tells me they're both wrong. Thanks a lot!

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The time doesn't start to rise until all the ice has melted. So you just need the sum of both times you already calculated.

So you're saying that the temperature won't start to rise over 0 until the ice has all melted? Seems like there could be other variables in play. That was the answer though, thanks a lot :). So simple it went right over my head.

Last edited:

## 1. How does thermodynamics explain the process of ice melting?

Thermodynamics explains the process of ice melting through the laws of energy conservation and heat transfer. When heat is applied to ice, the molecules gain enough energy to break their bonds and transition from a solid to a liquid state.

## 2. What factors affect the rate of ice melting?

The rate of ice melting is affected by the temperature of the surrounding environment, the surface area and shape of the ice, and the presence of substances such as salt or impurities which can lower the melting point of ice.

## 3. Can ice melt without a change in temperature?

Yes, ice can melt without a change in temperature if the surrounding environment is above the melting point of ice. This is because the heat energy from the environment is enough to break the bonds between the molecules and cause them to transition to a liquid state.

## 4. Does the process of ice melting follow the laws of thermodynamics?

Yes, the process of ice melting follows the laws of thermodynamics, specifically the first and second law. The first law states that energy cannot be created or destroyed, only transferred or converted. The second law states that heat will naturally flow from a higher temperature to a lower temperature.

## 5. How is thermodynamics related to the concept of entropy in ice melting?

Entropy is a measure of the disorder or randomness in a system. In the process of ice melting, the solid ice has a more ordered structure than the liquid water, therefore, the melting process increases the entropy of the system. This is in line with the second law of thermodynamics, which states that the overall entropy of a closed system will always increase.

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