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Entropy change for isobaric heating

  • Thread starter Alvine
  • Start date
  • #1
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Hi guys, is this right?

Homework Statement


A mole of nitrogen is heated at constant external pressure of 1 atm from 25° C to 100° C. The heat capacity of nitrogen is 29.1 J/mol·K.

Calculate ΔSsurr




2. The attempt at a solution
delta_S=Q/T = -1*29.1*75/373=-5.85 J/K

(heat transferred to the system divided by T_surr which we assume to be equal to T_final)

The solution in my lecture notes says -22 J/K, I can't see where that came from.
 

Answers and Replies

  • #2
lightgrav
Homework Helper
1,248
30
even if they heat it "infinitely slow", it only goes up to about 6½ J/K ,
no-where near 22 J/K .
{ they must've divided by 100 degrees C by mistake , rather than 373 K }
 

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