Maximum flame temperature during Combustion of CH4

In summary, the conversation was about calculating the maximum flame temperature of a reaction, with the answer being 4805K. However, the person asking for help made a mistake in their calculation and was corrected by the expert. The expert also noted that the heat capacity of N2 was given for a related question about combustion in different oxygen levels. The person asking for help apologized for their mistake and found a correct answer of 2280K for the related question.
  • #1
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3
Homework Statement
Combustion of CH4 at constant pressure (P=1bar).
Relevant Equations
CH4 (g) + 2O2 (g) --> CO2 (g) + 2H2O (g)
Enthalpy of reaction = -803 kJ.mol-1
Hi, I have to calculate the maximum flame temperature of the reaction above. The answer is 4805K but I didn't manage to obtain that answer. Please help me find my error, thank you so much! The values of C are below the solution attempt.
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  • #2
What does a flame that you can see consist of?
 
  • #3
Where you have written (Tf - 298)2, that should be (Tf2 - 2982). Correcting this gives 4805 K. But who says this is the right answer? Why do you think they give you the heat capacity of N2?
 
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  • #4
mjc123 said:
Where you have written (Tf - 298)2, that should be (Tf2 - 2982). Correcting this gives 4805 K. But who says this is the right answer? Why do you think they give you the heat capacity of N2?
Thank you sir! My excuses for my math. They gave the heat capacity of N2 for the following question that asks about the combustion in 20% O2 and 80% N2.
This question is for combustion in 100% O2.
But again, thank you so much for your help!
By the way, I found 2280K for the combustion in 20% O2 and 80% N2, that should be correct right?
 

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