Trouton constant, 368 Table

According to Ref 10a, Hydrazoic acid molecules are linked into an infinite zigzag chain by N—H... N hydrogen bonds. Thus its high value of specific heat of vaporization is not unexpected. A fairly reliable Trouton constant of 23.5 eu for hydrazoic acid also suggests a non-ideal associated liquid. The other three azides in Table 8 have specific heats of vaporization similar to those of nitrate esters and nitramines... 

Dimethylformamide and related solvents, such as dimethyl sulphoxide, have high Trouton constants and high dipole moments (Table 1, and... 

The Trouton constant of ethanol is about 28 cal./deg. mole, while most of the other substances have normal values. We have therefore taken c2 —1-4 the results are shown in fig. 28.2, where the points are numbered according to the serial numbers in table 28.1. To simplify the... 

For the diatomic interhalogen compounds listed in Table 12, Ip and Qa values are not much difierent. IBr and ICl are characterized as typical covalent molecules while for GIF and BrF an ionic character Qa 24 % and 30 %, respectively, is calculated. The Trouton constant of 28 e.u. for GIF is indicative of some tendency to association in the liquid state. 

This A p-S Tt,) value is typical for many other organic compounds that boil at very different temperatures (Table 4.2). In fact, long ago, Trouton (1884) recognized that the entropy of vaporization at the boiling point for many apolar and monopolar substances is more or less constant between 85 and 90 J moT1 K 1. Note that the constancy of A S Ti,) implies that there must be a close relationship between AmpH,(Tb) and Tb. 

Table 4.1 The structuredness of solvents, measured by their Trouton s constant, the entropy deficit, the dipole orientation correlation coefficient, and the heat capacity density...

As a general rule the value of the chemical constant is about 3 Another mteresting relation is that known as Troutons Law According to this law the molecular latent heat of vaporisation divided by the boiling point2 is a constant The limits of applicability will be seen from the following table (Lougumine s data, Wmkelmann s Handbuch, vol 111) —... 

In the following table are given the values of what are known as " Trouton s constants/ so far as they are required for the above three reactions they are calculated, both directly from the observed heats of evaporation and boiling-points and also from a very interesting formula given by Cederberg loc. cii., p. 55),... 

On the other hand, Eq. (6.88) allows to calculate the ebullioscopic constant by probing the elevation of the boiling point with a known solute with the aid of Trouton s rule. The dimensionless quantity Mi Tb/Kb in Table 6.2 equals to ASv/R. 

An empirical law known as Trouton s Law says that the entropy of vaporization is almost constant, about 20.3 cal mol K . Water has an anomalously large entropy of vaporization of about 26 cal mol Table 1.6 shows the entropy of vaporization divided by the gas constant R for different liquids. Note that the entropy of vaporization of ethanol is as large as that of water. 

Table 3.1.4 Some values of vaporization enthalpy, boiling temperature, and Trouton s constant.

This ratio of the standard vaporization enthalpy Ay pH° to the normal boiling temperature (at 1 bar), that is, the standard vaporization entropy AvapS , is called Trouton s constant Frederick Trouton, see box). Table 3.1.4 indicates that the values of AvapS are in the range 70-110 Jmol K , and we can use 90 J mol as a... 

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