Finding entropy change when house leaks heat

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 3K views
rubenhero
Messages
41
Reaction score
2

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!
 
Physics news on Phys.org
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!