Latent Heat (enthelpy) of Fusion changes with Pressure?

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SUMMARY

The discussion centers on the relationship between pressure and the latent heat of fusion, specifically whether the latent heat of fusion decreases linearly as pressure increases. The equation relating the entropy of fusion to the enthalpy of fusion is defined as ΔH = TΔS, where T represents the melting temperature. Participants clarify that while melting is often considered isothermal, the effects of pressure on melting point and latent heat are significant, with the enthalpy change being calculable from the difference in enthalpy before and after melting.

PREREQUISITES
  • Understanding of thermodynamic principles, specifically latent heat and enthalpy.
  • Familiarity with the equation ΔH = TΔS relating entropy and enthalpy.
  • Knowledge of isothermal versus isentropic processes in phase changes.
  • Basic grasp of the concepts of pressure and temperature in thermodynamics.
NEXT STEPS
  • Research the effects of pressure on melting points in different materials.
  • Study the relationship between enthalpy and entropy in phase transitions.
  • Explore isentropic versus isothermal processes in thermodynamics.
  • Learn about the calculation of latent heat in various states of matter.
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Students and professionals in thermodynamics, materials science researchers, and anyone interested in the effects of pressure on phase changes and latent heat calculations.

Hypatio
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If the melting point depends on the pressure, does the latent heat of fusion also depend on the pressure? The equation relating the entropy of fusion to the enthalpy of fusion is given by:

\Delta H=T\Delta S

where T is, apparently, the temperature of melting. So, if the melting point increases with pressure, then as isentropic melting occurs the latent heat (enthalpy) of fusion decreases linearly?
 
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Hypatio said:
If the melting point depends on the pressure, does the latent heat of fusion also depend on the pressure? The equation relating the entropy of fusion to the enthalpy of fusion is given by:

\Delta H=T\Delta S

where T is, apparently, the temperature of melting. So, if the melting point increases with pressure, then as isentropic melting occurs the latent heat (enthalpy) of fusion decreases linearly?

What do you mean with isentropic melting? Usually one considers melting at fixed temperature, i.e. isothermal melting.

Generally
<br /> dH=C_p dT +(V-T \frac{\partial V}{\partial T}|_p}dp<br />
with the last term in the brackets defines the isobaric thermal expansion coefficient.
Just integrate along the phase boundary T_\mathrm{melt}(p) for the two phases in equilibrium.
 
Hello Sir,
Latent heat of anything can simply be calculated by taking the difference between enthalpy after and before.

I dont' remember but the dependence of the enthalpy before and after will tell you if it will change the latent heat.
 

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