Consider the reaction of carbon monoxide with oxygen to produce carbon dioxide.
ID: 797072 • Letter: C
Question
Consider the reaction of carbon monoxide with oxygen to produce carbon dioxide.
2CO(g) + O2(g) -> 2 CO2(g)
At what temperature will this reaction be spontaneous according to Gibb's Energy?
DeltaH in kJ/mol for: CO(g) = -110.5, CO2(g) = -393.5
DeltaS in J/mol K for: CO(g) = 197.6, CO2(g) = 213.6, O2 = 205.0
This question was from my quiz and was a multiple choice question, the answer was "temps below 3273K" I'm not sure entirely if this question is asking for an estimate considering enough information might not be given, but an explanation of how you would go about doing it will be rewarded.
Explanation / Answer
deltaH = delta H product - delta H reactant = delta H (CO2) - delta H (CO)
= (2mol * -393.5 ) - ( 2mol * -110.5) = -566 kJ = -566,000 J
deltaS = delta S product - delta S reactant = delta S (CO2) - [delta H (CO) + delta H (O2)]
= (2mol * 213.6) - (2mol * 197.6 + 205)
= -173 J
delta G = deltaH - T * deltaS
If deltaG < 0 -> reaction is spontaneous -> delta H - T* delta S < 0
=> -566,000 - (-173T) < 0 (solve for T)
=> 173T < 566,000
=> T < 3271.67 K (really close to 3273K)