How Do You Calculate Entropy Changes in Thermodynamics?

Click For Summary
SUMMARY

The discussion focuses on calculating entropy changes in thermodynamics for the cooling of 1 mol of O2 gas from 298 K to liquid O2 at 90.19 K. The process is analyzed under both reversible and irreversible conditions, with specific attention to the enthalpy change of vaporization at 6820 J/mol and the heat capacity (Cp) of 7/2 R for the gas. Participants are encouraged to apply thermodynamic principles to determine the entropy changes for the system, surroundings, and universe.

PREREQUISITES
  • Understanding of thermodynamic concepts, specifically entropy and enthalpy.
  • Familiarity with the Clausius-Clapeyron equation for phase changes.
  • Knowledge of heat capacity calculations and their implications in thermodynamics.
  • Ability to differentiate between reversible and irreversible processes in thermodynamic systems.
NEXT STEPS
  • Study the Clausius-Clapeyron equation to understand phase transitions.
  • Learn how to calculate entropy changes for reversible and irreversible processes.
  • Explore the concept of heat capacity and its role in thermodynamic calculations.
  • Review examples of entropy calculations in thermodynamic systems to solidify understanding.
USEFUL FOR

This discussion is beneficial for students in physical chemistry, thermodynamics enthusiasts, and anyone seeking to deepen their understanding of entropy changes in phase transitions.

rafaela.nita
Messages
1
Reaction score
0
Thermodynamics for P Chem NEEd HELP By tomorrow!

Homework Statement



What are the values of the entropy changes (system, surroundings, and universe) for the cooling of 1 mol of O2 (g) from 298 K to O2 (l) at 90.19 K if the process is done

a. Reversibly
b. Irreversibly

by placing the sample in liquid hydrogen at 13.96 K? Assume enthalpy change of vaporization is 6820 j/mol at 90.19 K and Cp = 7/2 R for the gas.

Homework Equations



How do you solve this problem for all types of entropy?(entropy changes (system, surroundings, and universe)


The Attempt at a Solution


Have no clue how to start it. Please help!
 
Physics news on Phys.org


Welcome. Please use this resource wisely. Posts that specify that you need help in the next 24 hours or shorter are probably not going to encourage many members to help you. If you let your problem get that urgent, the motivation to help you will be minimal.
 

Similar threads

Chemistry No heat exchange with the surroundings in an irreversible expansion of an ideal gas?
  • · Replies 4 ·
Replies
4
Views
3K
Chemistry A calculation of enthalpy, entropy, and Gibbs energy of vaporization
  • · Replies 1 ·
Replies
1
Views
2K
Chemistry Entropy in isolated composite system for irreversible process
  • · Replies 3 ·
Replies
3
Views
3K
Calculate the change in entropy for the system and the surroundings
  • · Replies 13 ·
Replies
13
Views
4K
Chemistry How to reason about Gibbs energy change due to entropy not enthalpy?
  • · Replies 4 ·
Replies
4
Views
2K
Chemistry Two approaches to calculating entropy differ by factor of two. Why?
  • · Replies 3 ·
Replies
3
Views
3K
Calculate Work and Entropy Change for an Ice Maker
  • · Replies 1 ·
Replies
1
Views
2K
Calculating Entropy Change for N2O4 Equilibrium in Constant Pressure Vessel
  • · Replies 4 ·
Replies
4
Views
3K
Calculating Entropy Change for an Ideal Gas Expansion
  • · Replies 7 ·
Replies
7
Views
3K
Change in entropy of the surroundings in an irreversible process
  • · Replies 14 ·
Replies
14
Views
1K