Solubilities of naphthalene

Fig. 4. Vapor-phase solubility of naphthalene in ethylene. Data points from G. A. M. Diepen and F. E. C. Scheffer, J. Am. Chem. Soc. 70, 4085 (1948) vapor-phase fugacities from (---) Redlich-Kwong equation (-) Ideal gas law.

Figure 6.4 On the left is a phase diagram for carbon dioxide. Broken lines indicate isotherm crossing at either constant pressure or density. On the right is illustrated the change in solubility of naphthalene as a function of temperature and pressure.

Reported aqueous solubilities of naphthalene at various temperatures and empirical temperature dependence equations... 

Hilpert, S. (1916) The solubility of naphthalene in ammonia. A possible cause for naphthalene stoppages. Angew. Chem. 29, 57-59. 

Perez-Tejeda, P., Yanes, C., Maestre, A. (1990) Solubility of naphthalene in water and alcohol solutions at various temperatures. J. Chem. Eng. Data 35, 244—246. 

Supercritical solutions are characterized by very low solvent densities. As a result, they possess the interesting feature that solubility is determined more by solute-solute than solute-solvent interactions. Thus we were able to express the solubilities of naphthalene and a series of indole derivatives in four different supercritical solvents (C2H4, C2H6, C02 and the highly polar CHF3) in the same functional format, only the numerical coefficients varying from one to another.57 Solute-solvent interactions do occur,58 but solubility can be represented quite... 

In this equation, X2 represents the mole fraction of naphthalene in the saturated solution in benzene. It is determined only by the chemical potential of solid naphthalene and of pure, supercooled liquid naphthalene. No property of the solvent (benzene) appears in Equation (14.45). Thus, we arrive at the conclusion that the solubility of naphthalene (in terms of mole fraction) is the same in all solvents with which it forms an ideal solution. Furthermore, nothing in the derivation of Equation (14.45) restricts its application to naphthalene. Hence, the solubility (in terms of mole fraction) of any specified solid is the same in all solvents with which it forms an ideal solution. 

Kotula, 1. and Marciniak, B. Solubilities of naphthalene and acenaphthene in chloro derivative solvents, J. Chem. Eng. Data, 46(4) 783-787, 2001. 

Figure 10.15 illustrates the solubility of naphthalene in ethene as a function of pressure at 298 and 318 K. The solubility of naphthalene increases dramatically when passing the critical point of ethene (T. = 282 K, = 5 MPa). 

Figure 10.16 illustrates the solubility of naphthalene in supercritical ethene as a function of temperature at different pressures. In Fig. 10.16 the temperature dependence of solubility is different in different pressure areas. At high pressure, an increase in temperature is followed by an increase in solubility, whereas at lower pressures the opposite effect occurs. 

Fig. 10.16 Solubility of naphthalene in supercritical ethene as function of temperature at different pressures. 

Table 6.2 presents data showing the effect of various CMOS on the activity coefficient or mole fraction solubility of naphthalene, for two different solvent/water ratios. To examine the cosolvent effect, Schwarzenbach et al. (2003) compare the Hildebrand solubility parameter (defined as the square root of the ratio of the enthalpy of vaporization and the molar volume of the liquid), which is a measure of the cohesive forces of the molecule in pure solvent. 

A combined effect of natural organic matter and surfactants on the apparent solubility of polycyclic aromatic hydrocarbons (PAHs) is reported in the paper of Cho et al. (2002). Kinetic studies were conducted to compare solubilization of hydro-phobic contaminants such as naphthalene, phenanthrene, and pyrene into distilled water and aqueous solutions containing natural organic matter (NOM) and sodium dodecyl sulfate (SDS) surfactant. The results obtained after 72hr equilibration are reproduced in Fig. 8.19. The apparent solubility of the three contaminants was higher in SDS and NOM solutions than the solubility of these compounds in distilled water. When a combined SDS-NOM aqueous solution was used, the apparent solubility of naphthalene, phenanthrene, and pyrene was lower than in the NOM-aqueous solution. 

Size analyses of (using light scatter) some spherical micelles of SDS have indeed shown that the radius of the micelle is almost the same as the length of the SDS molecule. However, if the solute interferes with the outer polar part of the micelle, then the micelle system may change in such a way that the CMC and other properties change. This is observed in the case of the addition of dodecanol to SDS solutions. However, very small additions of solutes show very little effect on CMC. The data in Figure 3.18 show the change in the solubility of naphthalene in SDS aqueous solutions. 

Below CMC the amount dissolved remains constant, which corresponds to its solubility in pure water. The slope of the plot above CMC corresponds to 14 mole SDS 1 mol naphthalene. It is seen that, at the CMC, the solubility of naphthalene abruptly increases. This is because all micelles can solubilize water-insoluble organic compounds. A more useful analysis can be carried out by considering the thermodynamics of this solubilization process. 

The solubility of naphthalene in supercritical carbon dioxide fluids has been evaluated by means of the integral equation method (Tanaka and Nakanishi, 1994). 

An understanding of the phase behavior of a particular system of interest is important because complex results can sometimes occur. A dramatic example, which occurs frequently for solubilities in supercritical systems, is the retrograde behavior. Figure 3 clearly shows the presence of a retrograde region. For an isobaric system at some pressure, such as 12.7 MPa (1841.5 psi), an increase in temperature of a solution of ethylene and naphthalene from 300 to 320 K results in an increase in the equilibrium solubility of naphthalene. This behavior is typical of liquid solvent systems. For the same increase in temperature (300 to 320 K) but at a pressure of 8.1 MPa (1174.5 psi), the solubility of naphthalene decreases by nearly an order of magnitude. Because this latter behavior is the opposite of typical liquid solvents, it is termed retrograde solubility. 

Fig. 5. Solubility of naphthalene (squares) and phenanthrene (circles) in mixtures of toluene expanded with carbon dioxide at 25°C (1,0), in pure toluene...

Example 2. Estimate the solubility of naphthalene and methylparaben in water, using the group contribution method. 

McHugh, M. Paulaitis, M. E. Solid Solubilities of Naphthalene and Biphenyl in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1980, 25, 326-329. 

Najour, G. C. King, A. D. Solubility of Naphthalene in Compressed Methane, Ethylene, and Carbon Dioxide. Evidence for a Gas-Phase Complex Between Naphthalene and Carbon Dioxide. J. Chem. Phys. 1966, 45, 1915-1921. 

Tsekhanskaya, Yu. V. Iomtev, M. B. Mushkina, E. V. Solubility of Naphthalene in Ethylene and Carbon Dioxide Under Pressure. Russ. J. Phys. Chem. 1964, 38, 1173-1176. 

Fig. 2.2. The solubility of naphthalene in aqueous solutions of sodium cholate (c) and of Orange OT in solution of sodium decane-sulfonate ( ). The ratio between the increment in solubility (AS) and in concentration (AC) is plotted. The sodium decanesul-fonate solution displays the behavior typical of micelle formation with a well-defined CMC. (From Ref.24))...

Tsekhanskaya Yu. V., Iomtev M.B., Muskina E.V., "Solubility of naphthalene in ethylene and carbon dioxide under pressure", Russ. 

Figure 1 The solubility of naphthalene in CO2 as a function of pressure. Data from McHugh and Paulaltls.(22)...

Calculate the solubility of naphthalene in carbon tetrachloride at 20°C. The melting temperature of naphthalene is 80.2°C, the heat of fusion is 4562 cal/mole, and the... 

The solubility of naphthalene in carbon tetrachloride is calculated by Equation (3.20). However, the volume fraction of the solvent, rp, is unknown until x2 3S determined. First, cp2 = 1 is approximated. Then,... 

After the fifth iteration, the solubility of naphthalene in carbon tetrachloride is ... 

Table 5. Effect of Water Addition on the Solubility of Naphthalene (1) in Compressed Carbon Dioxide (2) at 340 K from grand canonical MC simulations h...

Erkey and Akgerman [8] reported an adsorption equilibrium constant for naphthalene in alumina pores filled with supercritical CO2. Analysis shows that this desorption equilibrium constant is simply proportional to the solubility of naphthalene in CO2 as measured by Tsekhanskaya et al. [9]. Hence, the desorption rate constant was estimated from the following type of correlation reported for the naphthalene-ethylene system by Tsekhanskaya et al. [9] ... 

In Figure 3 the equilibrium solubility of naphthalene in toluene expanded with carbon dioxide at 25°C is shown. There is a considerable deviation to the data of Dixon et al [2]. In both works, it was made sure that excess solids were present. Proper filtration of the naphthalene particles in situ prior to sampling is the crucial step of the experiment. Therefore, small amounts of particles leaking through the filter can cause an error in concentration determination. The samples in this work were analysed for naphthalene content by density measurement and additionally by refractive index measurement. The reproducability was better than 0.8 mole percent. 

Figure lQis a graph of naphthalene solubility in carbon dioxide at 45 C (15 C above the critical temperature of carbon dioxide) taken from Reference 17. As is obvious from an examination of the data, the solubility of naphthalene increases dramatically when the pressure is increased beyond the critical pressure of 73 atm. The solubility (given in units of grams/liter in the reference) approaches about 10% (w/w) at a pressure level of 200 atm. 

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