Irreversible Adiabatic Expansion (Physical Chemistry)

In summary, the problem involves an adiabatic expansion of 0.553mol of an ideal monatomic gas with a specific heat capacity of 3R/2. The initial state is defined by a pressure of 6.25bar and temperature of 306K. The final temperature needs to be calculated for an adiabatic expansion against an external pressure of 1.25bar to a final pressure of 1.25bar. To solve, the ideal gas law can be used to express the final volume in terms of the final temperature, which can then be substituted into the given equation to solve for the final temperature. This requires some algebra, but the final temperature can be determined.
  • #1
djh101
160
5

Homework Statement


Consider the adiabatic expansion of .553mol of an ideal monatomic gas with CV,m = 3R/2. The initial state is described by P = 6.25bar and T = 306K. Calculate the final temperature if the same gas undergoes an adiabatic expansion against an external pressure of P = 1.25bar to a final pressure P = 1.25bar.


Homework Equations


CVΔT = -PextΔV


The Attempt at a Solution


I need to find ΔT. P, V, and T are all variables, though, so I can't find ΔT because I don't know ΔV. What do I do?
 
Physics news on Phys.org
  • #2
Use the ideal gas law to express the final volume algebraically in terms of the final temperature. Substitute this into your equation. The final temperature will be on both sides of the resulting equation. Collect terms involving the final temperature, and solve for it.
 
  • #3
A little bit of annoying algebra, but I got it. Thank you very much.
 

1. What is irreversible adiabatic expansion in physical chemistry?

Irreversible adiabatic expansion is a process in which a gas expands without any heat exchange with its surroundings. This means that the temperature of the gas will change as it expands, but there is no external heat source or sink involved in the process.

2. How is irreversible adiabatic expansion different from reversible adiabatic expansion?

Reversible adiabatic expansion is a theoretical process in which a gas expands without any heat exchange and returns to its initial state after the process is reversed. In contrast, irreversible adiabatic expansion is a real-world process in which the gas cannot return to its initial state and some energy is lost in the form of work.

3. What is the equation for irreversible adiabatic expansion?

The equation for irreversible adiabatic expansion is PV^(γ) = constant, where P is the pressure, V is the volume, and γ is the specific heat ratio of the gas.

4. What factors affect irreversible adiabatic expansion?

The main factors that affect irreversible adiabatic expansion are the initial pressure and volume of the gas, the specific heat ratio of the gas, and any external work done on the gas during the expansion process.

5. What are the real-world applications of irreversible adiabatic expansion?

Irreversible adiabatic expansion is commonly seen in everyday devices such as refrigerators and heat engines. It is also used in industrial processes, such as in the expansion of gases in turbines and compressors.

Similar threads

I Irreversible adiabatic processes & entropy change (clarification needed)
    • Thermodynamics
Replies
22
Views
2K
Work and Volume in Adiabatic Expansion
    • Biology and Chemistry Homework Help
Replies
11
Views
3K
Entropy change in a irreversible adiabatic process
    • Biology and Chemistry Homework Help
Replies
7
Views
9K
I Focus Problem for Entropy Change in Irreversible Adiabatic Process
    • Thermodynamics
2
Replies
56
Views
3K
I Relation between change of pressure and temperature in adiabatic process
    • Calculus
Replies
1
Views
888
Adiabatic expansion of a real gas
    • Biology and Chemistry Homework Help
Replies
3
Views
6K
Thermodynamics: Compression of an Adiabatic Gas
    • Biology and Chemistry Homework Help
Replies
2
Views
1K
I Graphical difference between adiabatic and isothermal processes.
    • Thermodynamics
Replies
1
Views
612
Is this reaction reversible?
    • Biology and Chemistry Homework Help
Replies
2
Views
1K
Adiabatic Expansion of Pressurized Air in a Piston-Cylinder Setup
    • Introductory Physics Homework Help
Replies
8
Views
722

Hot Threads

Recent Insights

Back
Top