Acertain liquid has a vapor pressure of 92.0 torr at 23.0 °c and 313.0 torr at 45.0 °c. calculate the value of δh°vap for this liquid.

Given Data :

P 1=92 torr
P 2=313 
T 1=296 k
T 2=318 
Hvap = 47900 Joules
R=1.99 cal/mole-k 

Using Clausius-Clapeyron equation :
logP2/P1= delta H/(2.303*R) * (1/T1-1/T2)

log 313/92=0.53
2.303*R= 2.303*1.99
             = 4.5829 cal/mole-k
1/T1-1/T2=1/296 - 1/318
                =  0.0000233
delta H = 0.53*4.5829/0.000233
 delta H = 10424.622 cal

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