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Topic: How to find the quantity of ice melted?  (Read 7328 times)

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Offline jwxie

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How to find the quantity of ice melted?
« on: February 13, 2012, 02:49:22 AM »
So we are given an ice cube of unknown mass, and the goal is to determine the mass after putting it in the calorimeter.

We know the initial mass of the warm water. Is this the only way to solve the ice mass?
I looked it up and the purple font is my values. Please the image below.

http://i.imgur.com/NchJ5.png

Please tell me?

My friend said all I had to do is use Q = m * Heat of Fusion of ice where Q is the heat lost by warm water. I disagree with him because the there is actually two states of transformations:  from ice to cold liquid, and warm liquid <---> cold liquid. So there must be two states of phases changing.

Thank you very much!

Offline Rutherford

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Re: How to find the quantity of ice melted?
« Reply #1 on: February 13, 2012, 06:41:34 AM »
Maybe this way:
Q=Q1+Q2
Q is the heat that u need to bring to melt the ice
Q1 is the heat that u need to bring to raise the temperature of the ice to 273K
Q2 is the heat that u need to bring to break the intermolecular forces (so that you get from ice, water)
Q you can calculate with the calorimeter, and the inicial temperature of ice (I marked it with x).
Q=mc(273-x)+mλ---> m=Q/(c(273-x)+λ)

Offline jwxie

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Re: How to find the quantity of ice melted?
« Reply #2 on: February 13, 2012, 08:47:33 AM »
Maybe this way:
Q=Q1+Q2
Q is the heat that u need to bring to melt the ice
Q1 is the heat that u need to bring to raise the temperature of the ice to 273K
Q2 is the heat that u need to bring to break the intermolecular forces (so that you get from ice, water)
Q you can calculate with the calorimeter, and the inicial temperature of ice (I marked it with x).
Q=mc(273-x)+mλ---> m=Q/(c(273-x)+λ)
If lambda is Heat of fusion, and x is the initial temperature of ice, I suppose this equation is the same as the one I proposed?
Thanks.

Offline Rutherford

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Re: How to find the quantity of ice melted?
« Reply #3 on: February 13, 2012, 09:28:53 AM »
I don't know how it is called in English but I know that λ=333kJ/kgK, so I hope that we mean the same thing.

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