Standard Entropy of a liquid at melting point with no S(298.15) given

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The discussion revolves around calculating the standard entropy of a liquid at its melting point, given specific parameters including the melting point of 392.7 K, a Cp value of 250 J/mol K, and ΔSvap of 117.20 J/mol K. The Clausius-Clapeyron equation is applied to derive the enthalpy change (ΔH) and subsequently the entropy change (ΔS), resulting in a calculated value of 229.29 J/mol K, which does not match the expected answer of 350.60 J/mol K. Attempts to incorporate ΔSvap into the calculation yield a value of 346.5 J/mol K, indicating a discrepancy. The discussion highlights the challenge of determining the appropriate values for S2 and S1 to resolve the entropy calculation accurately. The need for clarification on the relationship between the derived entropy and the given ΔSvap is emphasized.
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Homework Statement


Vapour pressures of a liquid have been measured and fit to the following equation:
Log10 P (mmHg) = -3571/T + 8.999
The melting point has been determined to be 392.7 K.
A Cp value given for the liquid is 250 J/mol K
and the ΔSvap is 117.20 J/mol K

Homework Equations


Clausius Clapeyron:

ln(P1/P2)= ΔH/R*(1/T2 - 1/T1)

The Attempt at a Solution



T1= 392.7 K P1 = 0.8045 mmHg (from the equation, giving the vapour pressure of the LIQUID at the melting point).
T2= 298.15 K P2= 1.052E-3 mmHg

From the Clausius Clapeyron:

ln(0.8045 mmHg/1.052E-3 mmHg)= ΔH/R*(1/298.15 K - 1/392.7 K)

ΔH/R = 8221.89 K-1
ΔH = 68361 J/mol

ΔH/T = ΔS = 68361/298.15 = 229.29 J/mol K

However the answer is 350.60 J/mol K.

I tried adding the ΔSvap to the derived value (229.29+117.2) , however that only gives me 346.5 J/mol K
 
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Maybe this relation might be helpful: ##L = T\Delta S = T(S_2 - S_1)##.
 
I would use L= TΔS = 68361 J/mol = 229.29 J/mol K x 392.7 K
= 392.7(S2-S1),
At this point I am unsure what to use for S2 to solve for S1 or vice versa.
 

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