# thermo.solubility module¶

thermo.solubility.solubility_parameter(T=298.15, Hvapm=None, Vml=None, CASRN='', AvailableMethods=False, Method=None)[source]

This function handles the calculation of a chemical’s solubility parameter. Calculation is a function of temperature, but is not always presented as such. No lookup values are available; either Hvapm, Vml, and T are provided or the calculation cannot be performed.

$\delta = \sqrt{\frac{\Delta H_{vap} - RT}{V_m}}$
Parameters: Returns: T : float Temperature of the fluid [k] Hvapm : float Heat of vaporization [J/mol/K] Vml : float Specific volume of the liquid [m^3/mol] CASRN : str, optional CASRN of the fluid, not currently used [-] delta : float Solubility parameter, [Pa^0.5] methods : list, only returned if AvailableMethods == True List of methods which can be used to obtain the solubility parameter with the given inputs Method : string, optional A string for the method name to use, as defined by constants in solubility_parameter_methods AvailableMethods : bool, optional If True, function will determine which methods can be used to obtain the solubility parameter for the desired chemical, and will return methods instead of the solubility parameter

Notes

Undefined past the critical point. For convenience, if Hvap is not defined, an error is not raised; None is returned instead. Also for convenience, if Hvapm is less than RT, None is returned to avoid taking the root of a negative number.

This parameter is often given in units of cal/ml, which is 2045.48 times smaller than the value returned here.

References

 [R11241126] Barton, Allan F. M. CRC Handbook of Solubility Parameters and Other Cohesion Parameters, Second Edition. CRC Press, 1991.

Examples

Pentane at STP

>>> solubility_parameter(T=298.2, Hvapm=26403.3, Vml=0.000116055)
14357.681538173534

thermo.solubility.solubility_eutectic(T, Tm, Hm, Cpl=0, Cps=0, gamma=1)[source]

Returns the maximum solubility of a solute in a solvent.

\begin{align}\begin{aligned}\ln x_i^L \gamma_i^L = \frac{\Delta H_{m,i}}{RT}\left( 1 - \frac{T}{T_{m,i}}\right) - \frac{\Delta C_{p,i}(T_{m,i}-T)}{RT} + \frac{\Delta C_{p,i}}{R}\ln\frac{T_m}{T}\\\Delta C_{p,i} = C_{p,i}^L - C_{p,i}^S\end{aligned}\end{align}
Parameters: T : float Temperature of the system [K] Tm : float Melting temperature of the solute [K] Hm : float Heat of melting at the melting temperature of the solute [J/mol] Cpl : float, optional Molar heat capacity of the solute as a liquid [J/mol/K] Cpls: float, optional Molar heat capacity of the solute as a solid [J/mol/K] gamma : float, optional Activity coefficient of the solute as a liquid [-] x : float Mole fraction of solute at maximum solubility [-]

Notes

gamma is of the solute in liquid phase

References

 [R11251127] (1, 2) Gmehling, Jurgen. Chemical Thermodynamics: For Process Simulation. Weinheim, Germany: Wiley-VCH, 2012.

Examples

From [R11251127], matching example

>>> solubility_eutectic(T=260., Tm=278.68, Hm=9952., Cpl=0, Cps=0, gamma=3.0176)
0.24340068761677464

thermo.solubility.Tm_depression_eutectic(Tm, Hm, x=None, M=None, MW=None)[source]

Returns the freezing point depression caused by a solute in a solvent. Can use either the mole fraction of the solute or its molality and the molecular weight of the solvent. Assumes ideal system behavior.

\begin{align}\begin{aligned}\Delta T_m = \frac{R T_m^2 x}{\Delta H_m}\\\Delta T_m = \frac{R T_m^2 (MW) M}{1000 \Delta H_m}\end{aligned}\end{align}
Parameters: Tm : float Melting temperature of the solute [K] Hm : float Heat of melting at the melting temperature of the solute [J/mol] x : float, optional Mole fraction of the solute [-] M : float, optional Molality [mol/kg] MW: float, optional Molecular weight of the solvent [g/mol] dTm : float Freezing point depression [K]

Notes

MW is the molecular weight of the solvent. M is the molality of the solute.

References

 [R11261128] (1, 2) Gmehling, Jurgen. Chemical Thermodynamics: For Process Simulation. Weinheim, Germany: Wiley-VCH, 2012.

Examples

From [R11261128], matching example.

>>> Tm_depression_eutectic(353.35, 19110, .02)
1.0864594900639515