Physical Chemistry - vapor pressures

Click For Summary

Discussion Overview

The discussion revolves around determining the temperature at which isopropanol and carbon tetrachloride have the same vapor pressure, utilizing the Clapeyron equation and the provided boiling points and enthalpies of vaporization for each substance. The scope includes theoretical and mathematical reasoning related to physical chemistry concepts.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant suggests using the Clapeyron equation to solve the problem.
  • Another participant questions the meaning of boiling point and its relationship to vapor pressure.
  • A different participant states that boiling point is defined as the temperature where the vapor pressure equals the external pressure.
  • It is noted that with the given boiling points and enthalpies of vaporization, it is possible to find any p2/T2 pair for the substances.

Areas of Agreement / Disagreement

Participants generally agree on the relevance of the Clapeyron equation and the definition of boiling point in relation to vapor pressure. However, the discussion remains unresolved regarding the specific calculations needed to find the temperature at which the vapor pressures are equal.

Contextual Notes

Participants have not fully explored the assumptions underlying the Clapeyron equation or the specific mathematical steps required to reach a solution. There may be dependencies on definitions and conditions not yet clarified.

Who May Find This Useful

This discussion may be useful for students studying physical chemistry, particularly those interested in vapor pressure and phase changes of substances.

belltos
Messages
6
Reaction score
0

Homework Statement



At what temperature will isopropanol (Tbp = 82.5C) and carbon tetrachloride (Tbp = 76.7C) have the same vapour pressure? For isopropanol and carbon tetrachloride, the standard enthalpies of vaporization are 32.54 kJ mol-1 and 44.0 kJ mol-1, respectively.

Homework Equations


Clapeyron Equation?


The Attempt at a Solution


I don't really know how to get started.

Homework Statement




Homework Equations





The Attempt at a Solution



 
Physics news on Phys.org
You are right about using Clapeyron equation.

What does boiling point mean? How is it related to vapor pressure?

--
 
The only relationship I know between boiling point and vapor pressure is that the boiling point is the temperature where the vapor pressure of a liquid is equal to external pressure.
 
External pressure is 1 atm - that means you are given p1, T1 and vaporization enthalpy for each substance. That's enough to find any p2/T2 pair.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 19 ·
Replies
19
Views
4K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 10 ·
Replies
10
Views
8K