Finding entropy change when house leaks heat

AI Thread Summary
To find the change in entropy when heat leaks from a house, the total entropy change must account for both the loss inside and the gain outside. The heat loss from the house is calculated as ΔS = -Q/TH, while the heat gain outside is ΔS = Q/TL. The correct approach involves summing these two entropy changes to find the overall change. The final calculation yielded an entropy change of approximately 0.563 J/K, which was accepted as correct. Understanding both sides of the heat transfer is crucial for accurate entropy calculations.
rubenhero
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Homework Statement


b) The temperature inside a house is Tin = 19.2° C when the temperature outside is Tout = 10.7° C. If Q = 5.49 kJ of heat leak from the house to the outside, find the change in entropy caused by this process.


Homework Equations


W = QH - QC, dS = dQ/T


The Attempt at a Solution


dS = 5.49kJ/283.7K = .0193514276kJ/K

The answer I calculated was wrong, should I include the entropy inside the house?
Any help is appreciated!
 
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Hi rubenhero! :smile:

rubenhero said:

Homework Statement


b) The temperature inside a house is Tin = 19.2° C when the temperature outside is Tout = 10.7° C. If Q = 5.49 kJ of heat leak from the house to the outside, find the change in entropy caused by this process.


Homework Equations


W = QH - QC, dS = dQ/T


The Attempt at a Solution


dS = 5.49kJ/283.7K = .0193514276kJ/K

The answer I calculated was wrong, should I include the entropy inside the house?
Any help is appreciated!

Inside you lose ΔS=-Q/TH.
Outside you gain ΔS=Q/TL.

The question in your problem statement is not entirely clear, but I suspect the total change in entropy is intended, which is the sum of both entropy changes.
 
Thanks you for responding. You were right, I just did the sum of the entropy loss and gain and got an answer of .5629265733 J/K. Webassign marked my answer as right. Thanks again for your help!
 
You're welcome! :)
 
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