Problem about a block of ice melting (specific latent heat)

In summary, the conversation discusses the relationship between energy lost by water and energy gained by ice, with the equations provided being 0.16 x 4200 x (100-t) and 0.205 x L + 0.205 x (t) respectively. It is also mentioned that the temperature at thermal equilibrium is important and that t should be assumed to be 0 degrees C. This is necessary in order to solve for the latent heat of fusion.
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RateOfReturn
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Homework Statement
A mass of 160 g of water at 100 °C is poured into the hollow. The water has specific
heat capacity 4.20 kJ kg-1 K-1. Some of the ice melts and the final mass of water in the
hollow is 365 g.
(i) Assuming no heat gain from the atmosphere, calculate a value, in kJ kg-1, for the
specific latent heat of fusion of ice. [3]
Relevant Equations
E= mcΔt
E=ml
1683999244901.png


Energy lost by water = Energy gained by ice

Energy lost by water = 0.16 x 4200 x (100-t)
Energy gained by ice = 0.205 x L + 0.205 x (t) (where t is the temperature at thermal equilibrium). However, there does not appear to be enough info to continue.

The solution, however, considered t to be 0- whilst not explicitly mentioned in the questions is this because the water remaining in the hollow and to prevent further ice melting we can assume they must have the same temperature ?
1683999591377.png
 
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  • #2
RateOfReturn said:
The solution, however, considered t to be 0- whilst not explicitly mentioned in the questions is this because the water remaining in the hollow and to prevent further ice melting we can assume they must have the same temperature ?
Yes. We are to assume that the experimenter waited until an equilibrium was reached. An equilibrium with water and ice coexisting would naturally be at 0 degrees C.

The experimenter would be wise to do this because, as you noted, he otherwise would lack the ability to solve for the latent heat of fusion with the information that was collected.
 
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1. What is specific latent heat?

Specific latent heat is the amount of energy required to change the state of a substance from solid to liquid or from liquid to gas, without changing its temperature.

2. How is specific latent heat different from specific heat?

Specific heat is the amount of energy required to raise the temperature of a substance by 1 degree Celsius, while specific latent heat is the amount of energy required to change the state of a substance without changing its temperature.

3. Why is specific latent heat important in the melting of ice?

Specific latent heat is important in the melting of ice because it determines the amount of energy needed to change the state of the ice from solid to liquid. This energy is used to break the bonds between the molecules of ice, causing it to melt.

4. How does the specific latent heat of ice affect the melting process?

The specific latent heat of ice affects the melting process by determining how quickly the ice will melt. The higher the specific latent heat, the more energy is required to melt the ice, resulting in a slower melting process.

5. Can the specific latent heat of ice change?

No, the specific latent heat of ice is a constant value for a given substance. It does not change unless the substance itself changes. However, different substances have different specific latent heats, so the specific latent heat of ice may be different from the specific latent heat of other substances.

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