Heat capacity at constant volume explanation

In summary, the heat capacity at constant volume, CV, is the amount of heat needed to raise the temperature of a body at constant volume, while the heat capacity at constant pressure, CP, is the amount of heat needed to raise the temperature of a body at constant pressure. These two properties are related for an ideal gas by the fact that for a monatomic gas, CP is 5/2 times greater than CV, while for a diatomic gas, CP is 7/2 times greater than CV. This is because for an ideal gas, the internal energy only depends on the temperature, and for a monatomic gas, there are 3 degrees of freedom for translation and 0 for rotation, while for a diatomic gas
  • #1
imy786
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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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  • #2
What are [tex] C_p [/tex] and [tex] C_v [/tex] for monatomic and diatomic gases? You can pretty much find your answers to your questions in any standard physics textbook.
 
  • #3
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.
 
  • #4
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
 

1. What is heat capacity at constant volume?

Heat capacity at constant volume, also known as specific heat capacity, is the amount of heat required to raise the temperature of a substance by one degree Celsius while keeping its volume constant.

2. How is heat capacity at constant volume different from heat capacity at constant pressure?

Heat capacity at constant volume is measured under conditions where the volume of the substance does not change, while heat capacity at constant pressure is measured under conditions where the pressure of the substance remains constant. This means that the amount of heat required to raise the temperature of a substance will be different for these two types of heat capacity.

3. How is heat capacity at constant volume calculated?

Heat capacity at constant volume is calculated by dividing the amount of heat added to a substance by the change in temperature and the mass of the substance. The resulting value is expressed in units of J/K or cal/K.

4. What factors affect the heat capacity at constant volume of a substance?

The heat capacity at constant volume of a substance is affected by its molecular structure, mass, and the strength of intermolecular forces. Substances with more complex structures or stronger intermolecular forces tend to have higher heat capacities at constant volume.

5. Why is heat capacity at constant volume important in thermodynamics?

Heat capacity at constant volume is an important concept in thermodynamics because it allows us to understand and quantify the amount of heat required to raise the temperature of a substance. It also helps us understand the relationship between heat, temperature, and energy in various systems and processes.

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