Relation between temperature and boiling point?

Click For Summary
SUMMARY

The discussion centers on the relationship between latent heat of vaporization, temperature, and boiling point. It is established that the boiling point of a substance is determined by the equation $$T_{boil} = \frac {l_{23}}{s_{23}}$$, where $$l_{23}$$ represents latent heat and $$s_{23}$$ denotes entropy change during vaporization. The confusion arises from the understanding that while boiling point is influenced by external pressure, it is also intrinsically linked to temperature through the equilibrium vapor pressure. Thus, both temperature and pressure play critical roles in defining the boiling point.

PREREQUISITES
  • Understanding of latent heat of vaporization
  • Knowledge of Gibbs free energy and its implications in phase changes
  • Familiarity with the concepts of entropy and equilibrium vapor pressure
  • Basic principles of thermodynamics
NEXT STEPS
  • Study the relationship between Gibbs free energy and phase transitions
  • Explore the concept of equilibrium vapor pressure in detail
  • Investigate the effects of external pressure on boiling points of various substances
  • Learn about the latent heat of vaporization for different fluids and gases
USEFUL FOR

This discussion is beneficial for students and professionals in chemistry, physics, and engineering, particularly those interested in thermodynamics and phase change phenomena.

Decimal
Messages
73
Reaction score
7
Hello,

I am encountering some confusion with the relation between the latent heat of vaporization and the temperature of a substance. I understand both the latent heat and the entropy change of vaporization are dependent on the temperature, assuming the pressure is held constant. However given that the change in Gibbs energy for a phase change is equal to zero, one can express the boiling point of a substance in the latent heat and entropy change: $$ \Delta g = l_{23} - T_{boil} s_{23} = 0$$ $$T_{boil} = \frac {l_{23}}{s_{23}}$$ Here 2 and 3 refer to the fluid and gas states of the substance respectively. Doesnt this imply that the boiling point of a substance is dependent on the temperature? How can I interpret this? I always thought of the boiling point as a quantity dependent on the outside pressure.

Thanks!
 
Science news on Phys.org
You are aware that there is a one-to-one relationship between the temperature and the equilibrium vapor pressure, correct? And that boiling occurs when the equilibrium vapor pressure is equal to the outside pressure, correct?
 
  • Like
Likes   Reactions: Bystander

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
4
Views
3K
Replies
3
Views
2K
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
Replies
23
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K