Molar volume of ethanol

P rtl IMol r Properties. The properties of individual components in a mixture or solution play an important role in solution thermodynamics. These properties, which represent molar derivatives of such extensive quantities as Gibbs free energy and entropy, are called partial molar properties. For example, in a Hquid mixture of ethanol and water, the partial molar volume of ethanol and the partial molar volume of water have values that are, in general, quite different from the volumes of pure ethanol and pure water at the same temperature and pressure (21). If the mixture is an ideal solution, the partial molar volume of a component in solution is the same as the molar volume of the pure material at the same temperature and pressure. 

To a good approximation, what is the molar volume of ethanol vapor at 900(°F) [482.22°C] and 900(psia) [6,206 kPa] How does this result compare with the ideal-gas value ... 

The molar volume of ethanol at its boiling point can be estimated from the Rackett equation... 

Use the Hayduk and Minhas correlation for nonaqueous solutions. According to restriction 3 mentioned above, the molar volume of the acetic acid to be used in equation (1-54) should be VhA - 2 x 62.4 = 124.8 cm3/mol. The molar volume of ethanol is calculated from equation (1-48) VbB = 60.9 cm3/mol. Using the Mathcad routine developed in Example 1.9 gives... 

Depending upon the overall composition of a mixture, the molar volume of a substance can take very different values. The values can vary between the extremes of the pure state and the state of infinite dilution. Figure 8.3 shows how the molar volume of water depends upon the mole fraction of ethanol in an ethanol-water mixture at 298 K. The molar volume of ethanol is also dependent upon the... 

Figure 9.9 The partial molar volumes of ethanol Kg in ethanol-water mixtures as a function of ethanol mole fraction Xe for TIP3P (dotted line), TIP4P-EW [dot-dashed line),TlP5P-E (dashed line), SSDQOl (solid line), and...

It can be seen that at typical pressure differences (e.g., P Pf < 1 bar) in distillation processes the Poynting factors show values near unity. Because of the larger molar volume of ethanol, the deviation from unity is larger for ethanol than for water. 

Knoebel and Edmister studied the low-pressure compressibility of ethanol at 60, 80, and 100 °C, and reported values of B,. Coimsell et al. determined the molar volume of ethanol at the saturation vapour pressure,... 

Following are data on the density of ethanol-water solutions at 20°C. Calculate the volume of a solution containing 0.700 mol of water and the appropriate amount of ethanol for each of the data points except for the 0% and 100% data points. Determine the partial molar volume of ethanol at an ethanol mole fraction of 0.300, hy either graphical or numerical means. 

From the intercepts in Figure 4.3, determine the partial molar volumes of ethanol (substance 1) and water (substance 2) if the mole fraction of ethanol is equal to 0.500. The molar volumes of the pure substances are = 58.4cm mol , V 2 = 18.02 cm mol . ... 

Example 6.1 From the data shown in Figure 6.3 estimate the partial molar volume of ethanol in water solution at ethanol molalities of 0 and 1 molar, at 20°C. 

Example 6.4 Using Figure 6.5, estimate the partial molar volumes of ethanol and of water in a solution that is 1 molar in ethanol, by Eq. 6.17. 

Using the graphical method, determine the partial molar volume of ethanol at 25°C for the following mole fractions of species 1 ... 

Comelli, F. and Francesconi, R. Isothermal vapor-liquid equilibria measurements, excess molar enthalpies, and excess molar volumes of dimethyl carbonate + methanol. + ethanol, and propan-l -ol at 313.15 K. J. Chem. Eng. Data, 42(4) 705-709, 1997. 

Munoz, R., Burguet, M.C., Morlanes, N., and Garci a-Usach, F. Densities, refractive indices, and excess molar volumes of binary and tertiary systems containing isobutyl alcohol, ethanol, 2-methylpentane, and methyl ferf-butyl ether at 298.15 K, J. Chem. Eng. Data, 45(4) 585-589, 2000. 

Molarity of ethanolic KOH used to neutralise the excess AA + acetic acid = 0.505 M Volume of ethanolic KOH required to titrate 5 ml of reagent = 53.5 ml... 

Fig. 11.11 Flexibility of the organic zeolite structure (cf. Fig. 11.10 above) expressed in terms of molar volume of the empty space (calculated as the difference between the molar volume of the solid and the volume of the host) at equilibrium with mixed solvents acetone/4-methylpyridine and ethanol/4-methylpyridine...

Water, occasionally modified by a small volume of ethanol and electrolytes, is the universal food solvent. In this medium, a polysaccharide polyanion s molar volume (vm) is maximum, because charge repulsion forces the molecules into the stiff (uncurled) conformation of a rigid rod that cannot be extended further, but can be oriented (Odell, 1989). vm is larger for extended, stiff conformations than for compact random-coil conformations (Berth, 1992). As solvent quality deteriorates, e.g., by addition of salt or... 

Here Vi is the molar volume of the solute / incm3/(mol) at its normal boiling point (for some values of Vu see Tables 2.9a and b), p the viscosity of solvent in pP, i//. an association parameter for solvent, and T the absolute temperature in K. Recommended values of the association parameters are 2.6 for water, 1.9 for methanol, 1.5 for ethanol, and l.Ofor benzene, ether, heptane, and other unassociated solvents. Equation (2.82) should be used only for dilute nondissociating solutions. 

Quinary Mixed Solvent. The solubilities of naphthalene and anthracene in quinary mixed solvents (water/methanol/ ethanol/2-propanol/acetone) were predicted using Equation 23. The molar volume of an ideal quinary mixed solvent was calculated as... 

It may be noted that even in the case of a system comprising a solvent and a less dense antisolvent (e.g., ethanol-C02), that is, for vi > V2, the liquid molar volume of solution v first marginally decreases with Xi and then exceeds V2 at a high value of Xi. That is, a minimum in the molar volume occurs where V = vi = V2. However this may not be sharp at all. Even for a system in which the organic liquid solvent is lighter than CO2 (e.g., hexane, where vi < V2), the minimum value in the molar volume is also not prominent rather, it flattens out as Xi approaches unity. As a consequence, RMVE is insensitive to CO2 mole fraction Xi for several systems RMVE was earlier suggested by... 

Should one need to substantiate the existence of ions, certain measurements such as the lowering of the freezing point can be carried out [11]. If one takes each 1 molar solution of ethanol, sodium chloride and calcium chloride and determines the temperature at which the solutions begin to solidify (see E5.7), in an ideal case, one measures -1,9°C, -3,8°C and -5,7°C, respectively. Because freezing-point temperatures are not dependent on the type but rather on the number of particles per volume unit [11], it is concluded that... 

First, however, we convert from mass of C2H5OH to moles, using the compound s molar mass. Then we set up the mole-to-mole conversion, using the molar ratio of ethanol to carbon dioxide derived from the coefficients in the balanced equation. The next step is the new one we use the molar volume at STP to convert from moles of CO2 to volume of CO2 at STP. The sequence as a whole is... 

Compute the partial molar volumes of methyl foimate in methanol-methyl formate and ethanol-methyl formate mixtures at 298.15 K for various compositions using the experimental data in Fig. 8. l-2fl and the following pure-component data ... 

A partial molar property of a component in a mixture may be either greater than or less than the corresponding pure-component molar property. Furthermore, the partial molar property may vary with composidon in a complicated way. Show this to be the case by computing (a) the partial molar volumes and (b) the partial molar enthalpies of ethanol and water in an ethanol-water mixture. (The data that follow are from Volumes 3 and 5 of the International Critical Tables, McGraw-Hill, New York, 1929.)... 

---