Homework 8.41

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Drishti_Jain_1D
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Joined: Fri Jul 22, 2016 3:00 am

Homework 8.41

Postby Drishti_Jain_1D » Mon Jan 30, 2017 12:20 am

Homework Question 8.41 asks for a the final temperature when an ice cube has been placed in water at a certain temperature. Using the correct equations for heat and enthalpy, I am continuously getting the same answer for the final temperature: 33 degrees Celsius. However, the solutions manual says the answer is 31 degrees Celsius.
Is this problem just a rounding error or is there a conceptual error behind my answer?

Marie_Bae_3M
Posts: 25
Joined: Wed Sep 21, 2016 2:57 pm

Re: Homework 8.41

Postby Marie_Bae_3M » Mon Jan 30, 2017 1:30 am

I think it might be just because of rounding. Some of the problems I've been doing were off by about 0.2 when i used 8.314 J/(K*mol) instead of 8.32 J/(K*mol) from the solution guide, considering that there's also multiplication of huge numbers involved in this question too.
I actually got 31 celsius though and this is what i used:
50.0g(1mol/18.02g)(6.02KJ/mol)(1000J/KJ) + 50.0g(4.184J/(g*C))(Tf-C) = -(400.0g(4.184J/(g*C))(Tf-45C)


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