Equilibrium temperature with 2 states of matter

Click For Summary
SUMMARY

The discussion centers on calculating the equilibrium temperature when 35g of water vapor (H2O(g)) at 380K mixes with 300g of liquid water (H2O(l)) at 300K. The specific heat capacity of liquid water is given as Cp(l) = 4.18 kJ/K·kg, while the enthalpy of condensation is ΔH(condensation) = -2257 kJ/kg. The conclusion reached is that the heat capacities of H2O(g) and H2O(l) are indeed different, and using the same heat capacity for both phases leads to an incorrect equilibrium temperature estimate of 290K.

PREREQUISITES
  • Understanding of phase changes and thermodynamics
  • Knowledge of specific heat capacities for different states of matter
  • Familiarity with enthalpy concepts, specifically ΔH(condensation)
  • Basic skills in heat transfer calculations
NEXT STEPS
  • Research the specific heat capacity of water vapor (H2O(g)) at various temperatures
  • Study the principles of heat transfer during phase changes
  • Learn about the calculation of equilibrium temperatures in thermodynamic systems
  • Explore the concept of latent heat and its applications in phase transitions
USEFUL FOR

This discussion is beneficial for students and professionals in thermodynamics, chemical engineering, and environmental science, particularly those involved in heat transfer and phase change calculations.

jlau
Messages
1
Reaction score
0
You have to show your attempts, this is a forum policy. Also, all homework like questions should go to homework forum.
35g of h2o(g) at 380K flows into 300g of h2o(l) at 300K. Cp(l)=4.18kJ/K*kg and ΔH(condensation)= -2257kJ/kg.
I need to calculate the final temperature when the system reaches equilibrium.

Is the heat capacity for the h2o gas different than h2o liquid? Can you calculate heat capacity using ΔH(condensation)?

The answer I got when I used the same heat capacity was about 290K. Which I thought was odd considering the liquid water started at 300K and the gas was even hotter than that. could this be because heat was lost during condensation of the steam?
 
Last edited:
Physics news on Phys.org
jlau said:
Is the heat capacity for the h2o gas different than h2o liquid?

Yes.

Can you calculate heat capacity using ΔH(condensation)?

No.
 

Similar threads

Chemistry Equilibrium temperature of a water and ice system
  • · Replies 4 ·
Replies
4
Views
4K
Chemistry A calculation of enthalpy, entropy, and Gibbs energy of vaporization
  • · Replies 1 ·
Replies
1
Views
2K
4 very hard thermodynamics problems
  • · Replies 1 ·
Replies
1
Views
17K
Temperature after closing the valve
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Calculating vapor pressure from Boltzmann distribution?
  • · Replies 0 ·
Replies
0
Views
2K
Undergrad Is equilibrium vapor pressure different in vacuum and in air?
  • · Replies 2 ·
Replies
2
Views
3K
High School What causes the drop of latent heat at lower temperatures in liquid helium?
  • · Replies 2 ·
Replies
2
Views
3K
Chemistry homework help with enthelpy
  • · Replies 3 ·
Replies
3
Views
2K
Standard entropy of liquid lead at 500C?
  • · Replies 1 ·
Replies
1
Views
3K
Graduate Can Hamson-Linde cycle liquidize N2?
  • · Replies 7 ·
Replies
7
Views
3K