Solving for Heat Capacity and Ideal Gas Type in Thermodynamics

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SUMMARY

The discussion centers on determining the ratio of specific heats, \( \frac{C_p}{C_v} \), for an ideal gas undergoing adiabatic expansion and isothermal compression. The initial conditions include one mole of gas at 360K, expanding to double its volume, and then being compressed isothermally with a heat measurement of 1304J. Key equations utilized include \( TV^{\gamma-1} = \text{constant} \) for adiabatic processes and \( Q = RT \ln \frac{V_1}{V_2} \) for isothermal processes. The solution involves manipulating these equations to express \( C_p \) and \( C_v \) in terms of known variables.

PREREQUISITES
  • Understanding of ideal gas laws and behavior
  • Familiarity with thermodynamic processes: adiabatic and isothermal
  • Knowledge of specific heat capacities \( C_p \) and \( C_v \)
  • Ability to manipulate logarithmic and algebraic equations
NEXT STEPS
  • Study the derivation of the relationship between \( C_p \) and \( C_v \) for ideal gases
  • Learn about the implications of adiabatic and isothermal processes in thermodynamics
  • Explore the application of the ideal gas law in various thermodynamic scenarios
  • Review examples of calculating work done during adiabatic and isothermal processes
USEFUL FOR

Students and professionals in thermodynamics, particularly those studying ideal gas behavior and specific heat capacities, will benefit from this discussion.

bhoom
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Homework Statement


The temperature of one mole of ideal gas is 360K. The gas is allowed to expand adiabatically to the double volume. Then it is compressed isothermally to original volume. The specified amount of heat is measured at 1304J. Determine C_p / C_v, and specify the type of ideal gas were' talking about.


Homework Equations


So far I'v drawn a pressure/volume diagram and tried to express everything in terms of unknown p_1, unknown v_1 and known t_1. Then I'v kinda done just about anything I know in thermodynamics, but I'v got no clue in what I'm doing. I looked in the answers and just tried to manipulate my way the correct answer but so far I'm unsuccessful.
Another thing i tried is, since C_p and C_v is expressed in partial derivatives of the temperature and the last change in the gas was isothermic, i tried to manipulate the equations from that... right now I'm completely lost.



The Attempt at a Solution


No idea
 
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bhoom said:

Homework Statement


The temperature of one mole of ideal gas is 360K. The gas is allowed to expand adiabatically to the double volume. Then it is compressed isothermally to original volume. The specified amount of heat is measured at 1304J. Determine C_p / C_v, and specify the type of ideal gas were' talking about.

Homework Equations


So far I'v drawn a pressure/volume diagram and tried to express everything in terms of unknown p_1, unknown v_1 and known t_1. Then I'v kinda done just about anything I know in thermodynamics, but I'v got no clue in what I'm doing. I looked in the answers and just tried to manipulate my way the correct answer but so far I'm unsuccessful.
Another thing i tried is, since C_p and C_v is expressed in partial derivatives of the temperature and the last change in the gas was isothermic, i tried to manipulate the equations from that... right now I'm completely lost.

The Attempt at a Solution


No idea

Let's start with the relevant equations.

Let ##γ=\frac {C_p}{C_v}##.

In an adiabatic process ##TV^{γ-1}=constant##.
In an isothermal process ##Q=RT\ln \frac {V_1} {V_2}##.

You can find these equations for instance on wikipedia.Can you solve these equations for γ?
 
I like Serena said:
Let's start with the relevant equations.

Let ##γ=\frac {C_p}{C_v}##.

In an adiabatic process ##TV^{γ-1}=constant##.
In an isothermal process ##Q=RT\ln \frac {V_1} {V_2}##.

You can find these equations for instance on wikipedia.


Can you solve these equations for γ?

I got it now, thanks. My problem were how to express c_v and c_p.
 

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