Thermodynamics: gas expansion formula or approximation error?

In summary, the conversation involves two types of reversible processes, one involving CO2 being compressed from 380 mmHg to 1 atm at 127 °C, and the other involving oxygen expanding from 100 atm to 50 atm at 27 °C. The equations used are L = P1 * V1 * ln (P1 / P2) for both cases, and Q = L = -34.95 J and 349 * 10^3 J respectively. The pressure units used were atm and the units used in the evaluation were J. The question being asked is not clear.
  • #1
lucaud
1
0
Homework Statement
FIRST TYPE: REVERSIBLE PROCESS


SECOND TYPE: REVERSIBLE PROCESS
Relevant Equations
costant temperature
FIRST TYPE: REVERSIBLE PROCESS At the temperature of 127 ° C, 1 L of CO2 is reversibly compressed from the pressure of 380 mmHg to that of 1 atm. Calculate the heat and labor exchanged assuming the gas is ideal. Q = L = - 34.95 J

CONDUCT 380 mmHg = 0.5 atm L = P1 * V1 * ln (P1 / P2) = 0.5 * 1 * ln (0.5 / 1) = - 0.34 L * atm = -0.34 * 101325/1000 = -35.11 J

SECOND TYPE: REVERSIBLE PROCESS Calculate the maximum work obtainable by making 50 L of oxygen expand isothermally (27 ° C) from 100 atm to 50 atm. Suppose the gas has ideal behavior. 349 * 10 ^ 3 J

PROCESS: L = P1 * V1 * ln (P1 / P2) = 100 * 50 * ln (100/50) = 3465 L * atm = 3465 * 101325/1000 = 351165 J
 
Physics news on Phys.org
  • #2
Hello @lucaud , welcome !

You need to list the relevant equations you use and mention deviating units if necessary.
In this case the expression for work.

What are the units of pressure in the expression ?
What units did you use in the evaluation ?
 
  • #3
It seems to me your results are correct. What is your question?
 

1. What is the gas expansion formula in thermodynamics?

The gas expansion formula in thermodynamics is the ideal gas law, which states that the product of pressure and volume of an ideal gas is directly proportional to its temperature and number of moles. It can be represented as PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature.

2. How is the gas expansion formula used in real-life applications?

The gas expansion formula is used in various real-life applications, such as in the design of engines, refrigeration systems, and air conditioning systems. It is also used in the study of weather patterns and in the production of industrial gases.

3. What is the ideal gas law approximation error?

The ideal gas law is an approximation that assumes that gas molecules have no volume and do not interact with each other. However, in reality, gas molecules do have volume and interact with each other to a certain extent. This leads to a small error in the ideal gas law, which is known as the ideal gas law approximation error.

4. How can the ideal gas law approximation error be minimized?

The ideal gas law approximation error can be minimized by using a more accurate gas equation, such as the van der Waals equation, which takes into account the volume and intermolecular interactions of gas molecules. Additionally, the error can be reduced by using a lower pressure and higher temperature, as the ideal gas law is more accurate under these conditions.

5. What are some limitations of the gas expansion formula in thermodynamics?

One limitation of the gas expansion formula is that it is only applicable to ideal gases, which do not exist in reality. It also assumes that the temperature and pressure of the gas remain constant during expansion, which is not always the case. Additionally, the formula does not take into account the effects of non-ideal conditions, such as high pressures and low temperatures.

Similar threads

Entropy Change - Irreversible Isothermal Compression
    • Introductory Physics Homework Help
Replies
5
Views
3K
Thermodynamics - Question with my answer
    • Introductory Physics Homework Help
Replies
4
Views
2K
Change in entropy of an ideal gas during thermodynamic cycle
    • Introductory Physics Homework Help
Replies
1
Views
1K
Adiabatic Expansion of Pressurized Air in a Piston-Cylinder Setup
    • Introductory Physics Homework Help
Replies
8
Views
726
I Focus Problem for Entropy Change in Irreversible Adiabatic Process
    • Thermodynamics
2
Replies
56
Views
3K
PV Diagram Problem: Calculate Net Heat & Work Done
    • Introductory Physics Homework Help
Replies
2
Views
1K
Thermodynamics of a Single-Component Ideal Gas
    • Introductory Physics Homework Help
Replies
1
Views
794
Calculate the work in Joules by the Acetylene gas
    • Introductory Physics Homework Help
Replies
4
Views
3K
I Irreversible adiabatic processes & entropy change (clarification needed)
    • Thermodynamics
Replies
22
Views
2K
Ideal gas laws dealing with pressure volume and temp.
    • Introductory Physics Homework Help
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top