Vapor pressure data are given here for 1nitropropane GEN02 T

Vapor pressure data are given here for 1-nitropropane, GE,N02 Temperature (CC) Vapor Pressure (mm Hg) 25 50. 75 100 21.0 66.2 415.1 Use the Clausius-Claperon equation to calculate the molar enthalpy of vaporization o Molar enthalpy-LkJ/mol Normal boiling point K

Solution

According to Clausius-Clayperon equation,
ln (P\'/P) = (-L/R) x [(1/T\') - (1/T)]
Where
P\' = vapour pressure at 25oC = 21.0 mm Hg
P = vapour pressure at 50 oC = 66.2 mm Hg
R = gas constant = 8.314 J/(mol-K)
T\' = initial temperature = 25 oC = 25+273 = 298K
T = final temperature = 50 oC = 50+273 = 323K
L = heat of vaporization of this substance = ?
Plug the values we get
ln (P\'/P) = (-L/R) x [(1/T\') - (1/T)]
L = - [ln (P\'/P) xR] / [ [(1/T\') - (1/T)]]

= 36.753*10^3 J/ mol

= 36.752kJ/ mol