Increasing the Melting Point via Pressure Increase

Click For Summary
SUMMARY

The discussion focuses on determining the pressure required to increase the melting temperature of a substance by 20 degrees Celsius. Key parameters include the molar volumes of the solid (18.92 cm³) and liquid (19.47 cm³) phases. The Clapeyron relation is highlighted as a critical tool for solving this problem, emphasizing that an increase in pressure favors the denser solid phase, thus raising the melting point. Participants noted the challenge of calculating latent heat, which is not necessary for this specific problem as it can be approached using changes in entropy.

PREREQUISITES
  • Understanding of the Clapeyron relation
  • Knowledge of molar volumes for solid and liquid phases
  • Familiarity with phase transitions and thermodynamic principles
  • Basic concepts of entropy and latent heat
NEXT STEPS
  • Research the Clapeyron equation and its applications in phase transitions
  • Study the relationship between pressure, temperature, and phase changes in materials
  • Learn how to calculate molar and specific entropy for different phases
  • Explore methods for determining latent heat values for various substances
USEFUL FOR

Students and professionals in chemistry and materials science, particularly those studying phase transitions and thermodynamic properties of substances.

N8
Messages
6
Reaction score
0
1. What is the pressure needed to increase the melting temperature by 20 centigrade degrees?

Given: Molar Volume (solid) at normal melting temp is 18.92 cm^3
Given: Molar Volume (liquid) at normal melting temp is 19.47 cm^3

Homework Equations



delta H (s>l) = T(melting point)* delta S(s>l)

The Attempt at a Solution



Not sure how I can even come up with an equation. I know I can calculate the change in volume with the molar volumes. The equation listed doesn't seem to help any either, anyone have an equation that works?

dP/dT = L/TdeltaV can't be used since I don't know latent heat...

Please help~
 
Physics news on Phys.org
Look into the Clapeyron relation. An increase in pressure energetically favors the denser phase (solid) and therefore increases the melting temperature.
 
Well I don't know the latent heat energy (it can be found, but the book is suggesting you can solve the problem without it, and without the actual melting point but simply knowing the change in melting point)
 
The problem can also be solved if you know the molar or specific entropy of the solid and the liquid.
 

Similar threads

Why is solid density used in this thermodynamics problem?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Melting point of graphite and diamond?
  • · Replies 3 ·
Replies
3
Views
5K
Reduce Melting Temp. by applying Pressure
  • · Replies 5 ·
Replies
5
Views
3K
Calculate the latent heat of fusion of ice
  • · Replies 6 ·
Replies
6
Views
4K
Standard Entropy of a liquid at melting point with no S(298.15) given
  • · Replies 2 ·
Replies
2
Views
2K
Why is there a difference ?Melting Point of Lead & Tungsten: Find RMSA
  • · Replies 1 ·
Replies
1
Views
2K
Connection between increase in pressure and melting point
  • · Replies 1 ·
Replies
1
Views
1K
Melting of substance with -ve slope for fusion curve
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Melting point of ice decreases with increase in pressure
  • · Replies 1 ·
Replies
1
Views
5K
How to understand this 3d surface of ##P,\bar{V}##, and ##T##?
  • · Replies 11 ·
Replies
11
Views
3K