Equilibrium Temperature and composition

Click For Summary
SUMMARY

The discussion focuses on calculating the equilibrium temperature and composition of a mixture formed by adding 1.0 kg of ice at -40°C to 1.0 kg of water at 5.0°C. The established solution indicates that the final equilibrium state consists of 1.2 kg of ice and 0.80 kg of water, all at 0°C. The key equations used in the calculations include the heat transfer equations Q = mcΔT and Q = mL, which are essential for determining the heat exchange between the ice and water.

PREREQUISITES
  • Understanding of thermodynamics principles, specifically heat transfer.
  • Familiarity with the concepts of specific heat capacity and latent heat.
  • Knowledge of phase changes in matter, particularly melting and freezing points.
  • Ability to apply the equations Q = mcΔT and Q = mL in practical scenarios.
NEXT STEPS
  • Study the concept of specific heat capacity in detail, focusing on water and ice.
  • Learn about latent heat and its role in phase changes, particularly in melting and freezing processes.
  • Explore thermodynamic equilibrium and how to calculate it in different systems.
  • Practice problems involving heat transfer and phase changes to solidify understanding.
USEFUL FOR

This discussion is beneficial for students studying thermodynamics, particularly those tackling problems related to heat transfer and phase changes. It is also useful for educators looking for examples to illustrate these concepts in a classroom setting.

RedBarchetta
Messages
49
Reaction score
1

Homework Statement


Describe the composition and temperature of the equilibrium mixture after 1.0 kg of ice at -40*C is added to 1.0 kg of water at 5.0*C.

Homework Equations


<br /> \begin{gathered}<br /> Q = mc\Delta T \hfill \\<br /> Q = mL \hfill \\ <br /> \end{gathered} <br />

Book answer:1.2kg ice, 0.80 kg water, all at 0*C

The Attempt at a Solution



I'm not quite sure how to set this one up. I've tried:

<br /> m_i c_i \Delta T_i + m_w c_w \Delta T_w = 0<br />

With this I found the equilibrium temperature to be -9.8*C...
 
Physics news on Phys.org
To begin writing down the equations to yield the equilibrium temperature, the first thing one has to do is to determine the phase of matter the equilibrium point.

So, to start, you need to quantitatively compare the amount of heat required to raise the temperature of ice to 0 degC, heat absorbed from the water to decrease the temperature to 0 degC, and the heat required to freeze/melt all the water/ice. At which phase does the heat removed from the water= heat absorbed by the ice?
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
1K
Replies
2
Views
2K
Replies
12
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
14
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
9
Views
1K