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.

Question

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.