Heat capacity at constant volume explanation

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SUMMARY

The heat capacity at constant volume (CV) is defined as the heat input (Q) required to raise the temperature of a body at constant volume, while the heat capacity at constant pressure (CP) is the heat input needed for the same temperature increase at constant pressure. For ideal gases, CP is generally greater than CV due to the additional work done against atmospheric pressure during expansion. Specifically, the molar heat capacity for a monatomic gas is 5R/2 and for a diatomic gas is 7R/2, highlighting the theoretical and practical significance of these properties in thermodynamics.

PREREQUISITES
  • Understanding of thermodynamic concepts such as heat capacity
  • Familiarity with ideal gas laws
  • Knowledge of monatomic and diatomic gas properties
  • Basic grasp of thermodynamic processes at constant volume and pressure
NEXT STEPS
  • Study the derivation of heat capacities for ideal gases
  • Explore the implications of CP and CV in real-world thermodynamic processes
  • Investigate the relationship between heat capacity and molecular structure
  • Learn about the applications of CP and CV in engineering and physics
USEFUL FOR

Students of thermodynamics, physicists, and engineers interested in understanding heat capacities and their applications in various processes involving gases.

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Homework Statement



Explain what is meant by the heat capacity at constant volume, CV, and the heat capacity at constant pressure, CP.

How are these two properties related for an ideal gas?

Why is CP generally greater than CV


Homework Equations





The Attempt at a Solution



heat capacity at constant volume- CV- as the heat input, Q, needed to warm a body, divided by the corresponding temperature rise , where the temperaute rise is small, and the heating is carried out at constant volume


heat capacity at constant pressure, CP. As the heat input, Q, needed to warm a body, divided by the corresponding temperature rise, where the temperaute rise is small, and the heating is carried out at constant pressure,


CV- theortical importance
cp- practical importance
 
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What are C_p and C_v for monatomic and diatomic gases? You can pretty much find your answers to your questions in any standard physics textbook.
 
Both cv and vp are used in practice.
Cp is used maybe a little bit more often because many processes happen at a constant pressure.
The pressure can be the atmospheric pressure.
Or the pressure can be higher but it is often controlled to be constant, for various reasons including safety.
 
Why is CP generally greater than CV?

coz Cp is used more often because more processes at constant pressure.

-----------------------------------------------------

How are these two properties related for an ideal gas?

Cp molar heat capacity of a monatomic gas is 5R/2
and for diatomic gas is 7R/2
 

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