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posted by  Click here on 4/6/2008 6:26:55 PM  |  status: Closed  

Help cant get this question webassign

Course Textbook Chapter Problem
General Chemistry N/A N/A N/A
Question Details:
Consider the decomposition of calcium carbonate. Assume that H° = 177.8 kJ/mol and S° = 160.5 J/K·mol for the temperature range.

CaCO3(s) CaO(s) + CO2(g)

(a) Calculate the pressure in atm of CO2 in an equilibrium process at 25°C.
wrong check mark
Your answer differs from the correct answer by orders of magnitude. atm
(b) Calculate the pressure in atm of CO2 in an equilibrium process at 779°C.
atm
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posted by Jbroncos06balla on 4/6/2008 6:59:42 PM  |  status: Live
Asker's Rating: Lifesaver   
Click here's comment:
"Thank you so much "Rock chalk Jayhawk""
Response Details:
PART (a):
 
ΔGo   =   ΔHo - TΔSo
ΔGo   =   (177.8e3 J/mol) - (298 K)(160.5 J/K mol)
ΔGo   =   130.0e3 J/mol
 
Pco2   =   Kp   =   e ^ (-ΔGo / RT)
                       =   e ^ (-130.0e3 J/mol / (8.314 J/K mol)(298K))
                       =   e ^ (-52.47)
Pco2                =   1.65e-23 atm
 
PART (b):
 
ΔGo   =   ΔHo - TΔSo
ΔGo   =   (177.8e3 J/mol) - (1052 K)(160.5 J/K mol)
ΔGo   =   8.95e3 J/mol
 
Pco2   =   Kp   =   e ^ (-ΔGo / RT)
                       =   e ^ (-8.95e3 J/mol / (8.314 J/K mol)(1052K))
                       =   e ^ (-1.0237)
Pco2                =   0.359 atm
 
 
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