What is the correct solution for the temperature expansion problem?

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Homework Help Overview

The problem involves determining the temperature increase required to raise the pressure in a steel container filled with alcohol by 6 bar, given the compressibility of alcohol and the coefficients of thermal expansion for both alcohol and steel.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the original poster's calculation method and question the accuracy of the result, noting a discrepancy with the expected answer. Some participants suggest the possibility of a typo or error in unit conversion.

Discussion Status

The discussion is ongoing, with participants examining the correctness of the original poster's approach and calculations. There is acknowledgment of potential errors in the input values or the final answer, but no consensus has been reached regarding the resolution of the problem.

Contextual Notes

Participants are considering the implications of the coefficients provided and the assumptions made in the calculations, including the validity of the input values and the interpretation of the problem statement.

bolzano95
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Homework Statement


A steel container is filled with alcohol. For how much kelvins we have to raise the temperature for the pressure to be raised by 6 bar?
Compressibility of alcohol is
<br /> \kappa=1.15 \cdot 10^{-4} bar^{-1}<br />
temperature coefficient of volume expansion of alcohol is
<br /> \beta_a= 7.5 \cdot 10^{-4} K^{-1}<br />
temperature coefficient of length expansion of steel is
<br /> \alpha_s= 1.2 \cdot 10^{-5} K^{-1}<br />

Homework Equations


Look at attempt at solution.

The Attempt at a Solution


I solved this problem like this:
<br /> \frac{\Delta V}{V}=(\beta_a-3\alpha)\Delta T\\<br /> \frac{\Delta V}{V}=\kappa\Delta p\\<br /> \frac{\kappa\Delta p}{\beta_a-3\alpha}=\Delta T= 0.97K\\<br />
But the solution is wrong. The correct answer is 9.7K. I'm interested where I made a mistake.
 
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It looks like your answer is off by a factor of 10. This may be due to a typo or an error in the conversion of compressibility units to bar-1.
 
I checked and get 0.97K. Do you think the solving process is correct?
 
The method is correct. If you are certain that the input numbers are also correct, then the answer in the back of the book may be a typo.
 

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