solubility

All data and methods for estimating a chemical’s solubility.

thermosteam.properties.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
  • 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 [-]

Returns

  • 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

Other Parameters
  • 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.

Examples

Pentane at STP

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

References

1

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

thermosteam.properties.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 [-]

Returns

x – Mole fraction of solute at maximum solubility [-]

Return type

float

Notes

gamma is of the solute in liquid phase

Examples

From [1]_, matching example

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

References

1

Gmehling, Jurgen. Chemical Thermodynamics: For Process Simulation. Weinheim, Germany: Wiley-VCH, 2012.

thermosteam.properties.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]

Returns

dTm – Freezing point depression [K]

Return type

float

Notes

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

Examples

From [1]_, matching example.

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

References

1

Gmehling, Jurgen. Chemical Thermodynamics: For Process Simulation. Weinheim, Germany: Wiley-VCH, 2012.