Latent Heat (enthelpy) of Fusion changes with Pressure?

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The discussion centers on the relationship between pressure, melting point, and latent heat of fusion. It highlights that the melting point increases with pressure, which raises questions about whether the latent heat of fusion also varies with pressure. The equation ΔH = TΔS is referenced to relate the entropy and enthalpy of fusion, suggesting that if the melting point rises under pressure, the latent heat may decrease linearly during isentropic melting. However, there is a clarification that isentropic melting is not typically considered, as melting is usually analyzed under isothermal conditions. The conversation also touches on the calculation of latent heat, emphasizing that it can be determined by the difference in enthalpy before and after melting, with the dependence of enthalpy on pressure being crucial to understanding changes in latent heat.
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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