Temperature dependence of a latent heat.

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SUMMARY

The discussion focuses on calculating the enthalpy of sublimation for solid A at 300K using equilibrium vapor pressure data and heat capacity measurements. The Clausius-Clapeyron equation is applied to relate changes in pressure and temperature to the enthalpy of sublimation. The heat capacities provided are Cp(solid) = 40 J/(mol K) and Cp(vapor) = 40 + 0.1*T J/(mol K). A linear interpolation method is suggested to estimate the equilibrium vapor pressure at 300K, which is found to be 1.229 bar.

PREREQUISITES
  • Understanding of the Clausius-Clapeyron equation
  • Knowledge of heat capacity concepts
  • Familiarity with enthalpy calculations
  • Basic skills in linear interpolation methods
NEXT STEPS
  • Study the application of the Clausius-Clapeyron equation in phase transitions
  • Learn about calculating enthalpy changes using heat capacity data
  • Explore advanced interpolation techniques for thermodynamic data
  • Investigate the effects of temperature on vapor pressure in sublimation processes
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Chemistry students, thermodynamics researchers, and professionals involved in material science and phase transition studies will benefit from this discussion.

drivenbyfate
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Homework Statement


You Need to find the enthalpy of sublimation of solid A at 300K. The following equilibrium vapor pressure measurements have been made of pure A : (1) At 250K, the pressure is 0.258 bar and (2) At 350K, the pressure is 2.00 bar. The following heat capacity data is known:
Cp(solid) = 40 J/(mol K) ; Cp(vapor) = 40 + 0.1*T J/(mol K)

Calculate the enthalpy of sublimation, accounting for the temperature variation of the enthalpy of sublimation.

Homework Equations



Claussius-Clapeyron Eqtn: dP/P = ((delta H sublimation) / R) * (dT / T^2)
Change in Enthalpy (Ideal) = integral (Cp * dT)

The Attempt at a Solution



None. I cannot think of a way of including the temperature dependence of the heat of sublimation.
 
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drivenbyfate said:

Homework Statement


You Need to find the enthalpy of sublimation of solid A at 300K. The following equilibrium vapor pressure measurements have been made of pure A : (1) At 250K, the pressure is 0.258 bar and (2) At 350K, the pressure is 2.00 bar. The following heat capacity data is known:
Cp(solid) = 40 J/(mol K) ; Cp(vapor) = 40 + 0.1*T J/(mol K)

Calculate the enthalpy of sublimation, accounting for the temperature variation of the enthalpy of sublimation.


Homework Equations



Claussius-Clapeyron Eqtn: dP/P = ((delta H sublimation) / R) * (dT / T^2)
Change in Enthalpy (Ideal) = integral (Cp * dT)

The Attempt at a Solution



None. I cannot think of a way of including the temperature dependence of the heat of sublimation.
OK the simplest way to interpolate is linear interpolation, and in this way I find equilibrium vapor pressure of 1,229 Bar.
How do I get enthalpy from this?
greetings Janm
 

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