Thermodynamics: Heating gas in two separate containers

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SUMMARY

The discussion focuses on the thermodynamic analysis of heating gas in two separate containers with a movable piston. The initial conditions include equal pressure (P_0), volume (V_0), and temperature (T_0) on both sides, with the gas on the left being heated to increase the pressure on the right to (27*P_0)/8. The work done on the gas on the right is expressed as nTcv/2, but clarification is needed as it should align with the solution nT_0cv/2. The final temperatures of both gases and the heat flow into the gas on the left are also explored, with hints provided for further calculations.

PREREQUISITES
  • Understanding of ideal gas laws, specifically PV = nRT
  • Knowledge of thermodynamic concepts such as work, heat, and internal energy
  • Familiarity with specific heat capacities, cp and cv, and their relationship
  • Basic principles of thermodynamics, including the concept of adiabatic processes
NEXT STEPS
  • Study the derivation of work done in thermodynamic processes
  • Learn about the relationship between temperature change and internal energy in ideal gases
  • Explore the concept of adiabatic processes and their equations
  • Investigate the first law of thermodynamics and its application in gas systems
USEFUL FOR

This discussion is beneficial for physics students, thermodynamics enthusiasts, and engineers involved in heat transfer and gas dynamics, particularly those analyzing systems with ideal gases and movable pistons.

2DGamer
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1. A cylinder with thermally insulated walls contains a movable frictionless thermally insulated piston. On each side of the piston are n moles of an ideal gas. The initial pressure (P_0), volume (V_0), and temperature (T_0) are the same on both sides of the piston. The value for (gamma) is 1.5, and cv is independent of temperature. By the means of a heating coil in the gas on the left side of the piston, heat is supplied slowly to the gas on this side. It expands and compresses the gas on the right side until its pressure has increased to (27*P0)/8.

1) How much work is done on the gas on the right side in terms of n, cv, and T_0?
2) What is the final temperature of the gas on the right? (this is the only one I can solve)
3) What is the final temperature of the gas on the left?
4) How much heat flows into the gas on the left?




2. PV = nRT



3. For the first part where I need to find the work on the right side I noted that cp - cv = R. Also, since (gamma) = cp/cv I put these two together to get:
1.5 = (cv + R)/cv which equals: 1.5 = 1 + R/cv which equals: .5 = R/cv. Using the equation PV = nRT I replaced R with PV/nT, then solved for PV and got nTcv/2 which is the correct answer in the book, but I'm wondering if this is even the right way to do the problem. Aren't I supposed to start with the definition of work and go from there? I've tried that, but keep getting stuck.

For the second one I included my work in the attachment. I feel pretty good about that one.

For the third and fourth one I really have no idea how to even get started. If you can just give me a hint, that would be great.

 

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The reason your solution to part (1) doesn't feel right is that work doesn't equal PV, and your answer nTc_v/2 doesn't match the solution nT_0c_v/2. Try relating the energy gained by the gas on the right to its change in temperature, and working from there.
 

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