Change in internal energy in air

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SUMMARY

The discussion focuses on calculating the change in internal energy of 2500 moles of air when 300 kJ of heat is applied at constant pressure. The relevant equation involves degrees of freedom and the ideal gas law, specifically using the formula (f/x)nkT. Participants emphasize the importance of using the specific heat capacity (Cp) for air, which primarily consists of diatomic molecules such as nitrogen (N2) and oxygen (O2), to accurately determine the change in internal energy.

PREREQUISITES
  • Understanding of the ideal gas law
  • Knowledge of specific heat capacity (Cp) for diatomic gases
  • Familiarity with the concept of degrees of freedom in thermodynamics
  • Basic proficiency in thermodynamic equations
NEXT STEPS
  • Research the specific heat capacity (Cp) values for air and other diatomic gases
  • Learn how to calculate degrees of freedom for different molecular structures
  • Study the application of the first law of thermodynamics in constant pressure scenarios
  • Explore the relationship between heat transfer and internal energy changes in gases
USEFUL FOR

This discussion is beneficial for students and professionals in thermodynamics, particularly those studying heat transfer, internal energy calculations, and the behavior of gases under varying conditions.

S1CkFiSh
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If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy?

So far i think I use the equation: (f/x)nkT, but I don't know how to calculate the degrees of freedom and whether I do or not, and whether or not to calculate the number of moles by n=2500/6.022 x 10^23 (avogadro's constant), or if I just plug 2500 moles into n?
 
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S1CkFiSh said:
If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy?

So far i think I use the equation: (f/x)nkT, but I don't know how to calculate the degrees of freedom and whether I do or not, and whether or not to calculate the number of moles by n=2500/6.022 x 10^23 (avogadro's constant), or if I just plug 2500 moles into n?
Look up the Cp for air. It consists mainly of diatomic molecules (N2, O2), if you want to figure it out.

AM
 
ok, thank you very much its appreciated
 

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