Saturday
May 18, 2013

# Homework Help: heat of vapor pressure

Posted by yayhawknelson on Thursday, January 18, 2007 at 1:15am.

When a student plotted ln [vapor pressure of a gas] vs. inverse Kelvin temperature, she obtained a straight line with a slope equal to -9500 K.
According to the Clausius Clapeyron equation, Hvap is ?
kJ/mol.

The vapor pressure is proportional to
exp (-Hv/RT), with a constant of proprtionality I'll call C

When one plots ln Pv vs 1/T, the relationship is

ln (Pv) = ln V -Hv/RT
and the slope is -Hv/R.

If -Hv/R = -9500 K,
Therefore Hv = 9500 R,
where R is the molar gas constant, 1.987 cal/mole K

Hv is called the heat of vaporization, not the heat of vapor pressure.

My symbol Pv in my previous post represents the vapor pressure.

No one has answered this question yet.

Related Questions

chemistry(vapor pressure) - When a student plotted ln [vapor pressure of a gas] ...
chemistry - When a student plotted ln [vapor pressure of a gas] vs. inverse ...
chemistry - When a student plotted ln [vapor pressure of a gas] vs. inverse ...
Chemistry - When a student plotted ln [vapor pressure of a gas] vs. inverse ...
chem - When a student plotted ln [vapor pressure of a gas] vs. inverse Kelvin ...
Chemistry - When a student plotted ln [vapor pressure of a gas] vs. inverse ...
Chemistry - When a student plotted ln [vapor pressure of a gas] vs. inverse ...
Chemistry - 1. A gas initially at 10 C must be changed to _____ C to triple the ...
College Chemistry - The boiling point of a liquid at atmospheric pressure is the...
Calculating Vapor Pressure - The vapor pressure of nitrogen at several different...