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#1 2007-03-09 17:38:21
- 93BMW
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- Registered: 2007-03-08
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in dire need of help
In dire need of help
Steam at 100 deg C is added to ice at 0 deg C. The mass of the steam is 10 g and the mass of the ice is 50 g. what is the final temperature of the mixture
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#2 2007-03-09 18:32:57
- Stanley_Marsh
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Re: in dire need of help
Here is my opinion , though I 've never learned about Temp, Pressure, Gas.
If a water particle with 0 deg c encounter with a 100 deg c water particle , they will both become 50 deg c . The mass of the steam is 10 g and the mass of the ice is 50 g , imply that ice has 5 times particle that of the steam. So the final temp should be
Numbers are the essence of the Universe
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#3 2007-03-09 19:29:31
- ryos
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Re: in dire need of help
Hmm...that seems much too nice and neat to work. 
To check for sure, you'd need to find the total heat in the system and then convert that to temperature for 60g of water. I'll do that in the morning as I don't remember how off the top of my head and right now I don't have my book handy.
El que pega primero pega dos veces.
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#4 2007-03-10 00:30:50
- mathsyperson
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Re: in dire need of help
Ryos is right. Stanley's method works if you assume that no matter what temperature you are at, adding the same amount of energy will always increase the temperature by the same amount. This is not the case, although it's a fairly good approximation.
Unfortunately, things get even more complicated because as well as heating up or cooling down the water, some energy will be used to melt ice and some will be gained by condensing the steam.
So to get a true answer, you'd need to get some values from textbooks and plug them into a big long formula, but Stanley's answer is fine if you only want a rough guess.
Why did the vector cross the road?
It wanted to be normal.
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#5 2007-03-10 02:14:51
- Stanley_Marsh
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Re: in dire need of help
Oh right , the starting temp , there should be some formula?
Last edited by Stanley_Marsh (2007-03-10 02:15:18)
Numbers are the essence of the Universe
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#6 2007-03-10 07:02:16
- ryos
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Re: in dire need of help
Do you only want a rough guess? Because the real deal involves phase changes and that can get messy. Or there's the less-rough guess, which ignores the phase changes and just deals with total energy.
What'll you have? 
El que pega primero pega dos veces.
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