### Textbook Examples:

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**08.01 Solubility of Anthracene and Phenanthrene in Benzene (p. 395)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.02 SLE of Different Xylenes in Benzene (p. 395)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.03 SLE of Benzene – Ethanol Using UNIQUAC (p. 396)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.04 SLE in the Ternary Mixture of o-, m- and p-Xylene (p. 397)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.05 SLE of the Eutectic System CCl _{4} – n-Octane With Solid Phase Transition (p. 398)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.06 Ideal and Real Solubility of Naphthalene in the Mixture Ethanol – Isooctane (p. 399)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.07 Cryoscopic Constant of Water and Naphthalene (p. 402)**

no Mathcad solution required

**08.08 SLE of the Non-Eutectic System Anthracene – Phenanthrene (p. 402)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.09 SLE of the System D-Carvoxime – L-Carvoxime With a Congruent Melting Point (p. 404)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.10 SLE of the Non-Eutectic Mixture Diphenylacetylene – N,N-Diphenylhydrazine (p. 406)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.11 SLE of the System CCl _{4 }– p-Xylene With a 1:1 Adduct (p. 408)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**08.12 Ideal and Real Solubility of NaCl, KCl und NH _{4}Cl in Water (LIQUAC) (p.411)**

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

### Additional Problems:

**P08.01**** Solubility of Anthracene and Phenanthrene in Benzene and Ethanol (Ideal and Modified UNIFAC)
**Calculate the solubility of the isomeric compounds anthracene and phenanthrene in benzene and ethanol at 25 °C assuming ideal behavior and using the group contribution method modified UNIFAC.

Compare the calculated results with the solubilities measured at 25°C.

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.02**** Cryoscopic Constants of Benzene and Camphor **

Calculate the cryoscopic constants of benzene and camphor using the pure component data in the solution file.

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.03**** Freezing Point Depression of Naphthalene Using the Cryoscopic Constant
**Calculate the freezing point depression of naphthalene for the case that 0.2 g of benzene is added to 50 g naphthalene. (K

_{cry,naphthalene }= 6.96 K kg/mol, M = 128.173 g/mol)

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.04**** Molar Mass from Freezing Point Depression
**Calculate the molar mass of an unknown component which leads to a freezing point depression of 0.223 K of naphthalene, when 0.25 g of the unknown compound is added to 100 g naphthalene. (K

_{cry,naphthalene}= 6.96 K kg/mol)

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.05**** Mutual Solubility of Two Isomeric Xylenes**

Calculate the solubility of m-xylene (1) in p-xylene (2) and p-xylene (1) in m-xylene (2) at a temperature of 225 K.

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.06**** SLE of Eutectic Mixtures Using Ideal Behavior and Modified**

**UNIFAC
**Calculate the SLE diagram for the following binary eutectic systems

1,2,3-trichlorobenzene – n-decane and

1,2,4-trichlorobenzene – n-tetradecane

assuming

a) ideal behavior

b) taking into account the real behavior using modified UNIFAC

Compare the results with the published data in the solution file.

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.07 SLE of a System With 1:1 Compound Formation Assuming Ideal
Behavior
**Calculate the SLE behavior of the system p-toluidine-phenol with 1:1 compound formation assuming ideal behavior, where the melting point and enthalpy of fusion of the 1:1 compound should be adjusted to get a reliable description of the SLE behavior. Published data are listed here:

(file with published data)

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.08**** Solid CO _{2 }Solubility in Propane Using PSRK and VTPR
**Calculate the solubility of solid carbon dioxide in propane with the help of the group contribution equations of state PSRK and VTPR assuming simple eutectic behavior. Compare the results with the results assuming ideal behavior and the experimental data that can be downloaded below. All required parameters can be

found in Appendix A.

(file with published data)

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.09**** Enthalpy of Fusion from Solubility Data
**Estimate the enthalpy of fusion of benzene (1) by regressing the following solubility data of benzene in toluene assuming ideal (g

_{1 }= 1) and simple eutectic behavior.

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.10**** SLE of Eutectic and Ideal Ternary Mixture (Xylenes)**

Determine the solid-liquid equilibrium temperature of the ideal ternary system m-xylene (1) – o-xylene (2) – p-xylene (3) for a composition of x_{1} = 0.1 and x_{2} = 0.1 with the help

of the melting temperatures and enthalpies of fusion given in Example 8.4 in the textbook. Which component will crystallize?

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.11**** Eutectic Inside Miscibility Gap Possible?**

Is it, at least theoretically, possible that a eutectic binary mixture with liquid-liquid immiscibility shows a eutectic composition inside the miscibility gap?

solution solution video (large), (medium), (small)

**P08.12**** Regression and Prediction of SLE in DDB/DDBSP
**In the free DDBSP Explorer Version, search for solid-liquid equilibrium data for the mixture 2-propanol – benzene. Regress both datasets simultaneously using the Wilson, NRTL and UNIQUAC model.

Compare the performance of the three models. Compare the data to the results of the predictive methods UNIFAC, mod. UNIFAC and PSRK. Examine the different graphical representations.

solution solution video (large), (medium), (small)

**P08.13 SLE of Sucrose-Water Taking Into Account the Difference in Solid
and Liquid Heat Capacity
**For the calculation of the solubility of sucrose in water Peres and Macedo (A.M. Peres, E.A. Macedo, Fluid Phase Equilib. 123 (1996), p. 71-95) proposed the following physical property parameters:

missing

The solubility of sucrose in water at 25°C is 2.0741 per g water corresponding to a sucrose mole fraction of 0.09842. Calculate the activity coefficient of sucrose in water at 25°C at this concentration with and without taking into account the heat capacity difference between subcooled liquid and solid sucrose.

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS

**P08.14**** Vapor Pressures of Liquid and Solid Non-Eutectic Mixtures **

The vapor pressures of liquid anthracene and phenanthrene can be described by the Antoine equation using the Antoine parameters given below. Calculate the vapor-liquid-solid equilibrium (VLSE) along the solid-liquid saturation curve assuming ideal mixture behavior in the liquid phase. Melting points and heats of fusion of both components are

given in Example P08.01 above. Compare the vapor-liquid separation factors to those of an isothermal VLE data set at 220°C (calculate assuming ideal liquid mixture behavior).

Mathcad (2001) – Solution (zip)

Mathcad (2001) – Solution as XPS