Watson equation

If an experimental value of the latent heat at the boiling point is known, the Watson equation (Watson, 1943), can be used to estimate the latent heat at other temperatures. 

Of particular value in kinetic studies are residual plots using the linearized form of the Hougen-Watson equation. For the model of Eq. (18), for example, we obtain... 

Methods to Estimate pv from Tb Only The modified Watson correlation [2] applies for liquids and solids in the pv range from 10-7 to 760mmHg. This method is based on the Watson equation (8.5.1) and requires the input of the normal boiling point temperature, Tb, and of AHvb. However, the latter property is itself calculated from Tb and from structural parameters. For compounds with pv between 10 and 760mmHg, a method error of 2.5% has been reported, whereas a considerably higher error has been found for compounds with pv below lOmmHg. The method has been illustrated for benzene and DDT [2]. A large number of other Tb/pv correlations have been discussed by Horvath [17]. 

This section is limited to the method of Watson [25]. Watson s method allows the estimation of AHv at a given T, if Tb, Tc, and AHvb are known. The Watson equation is... 

The heats of vaporization at (lie boiling points have been reported In the literature M M These data were extended from - -MIT us the critical temperature by the Kharhanda nomograph of the Watson equation ... 

The heat of vaporization at the boiling point has been determined for IICN and acetonitrile.1- 5, 4i-uv The estimation technique of Velcrowas used to calculate the heat of vaporization of propionitrile and butronitrile The boiling point data were extended over a wide temperature range by the Kharbandu nomograph of the Watson equation." The overall error is probably 5r or less. 

The beat of vaporization at the boiling point con be ex tended over a wide temperature range by the Kharfoandu nomograph,1 which is based on (he Watson equation. 

For different temperatures, a widely used correlation between the enthalpy of vaporization and temperature is the Watson equation (14), with an average error of 2% ... 

Enthalpies Ideal gas for vapour, Watson equation for liquid. Densities Rackett equation. ... 

For the late metals where M-C bonds are less strong, CC bond activation seems always to need some special driving force, such as relief of strain, chelate assistance, or attainment of an aromatic product. For early metals, M-C bonds can be much stronger and simple CC bonds can be more easily cleaved. A classic early example from Watson (equation 1) requires chelate assistance but C-C cleavage can be competitive with the alternate CH bond cleavage (beta-elimination) that normally dominates ... 

The results are given in Table 7. For the tabulation, a modified Watson equation was selected for enthalpy of vaporization as a function of temperature ... 

The Faddeev-Watson equations have also provided new physical understanding in those cases where the interaction potential is given by a sum of pair-potentials. In molecular reactions however, the particles are atoms or ions and their internal structure play an essential role. As a result, the interaction potential is dominated by a three-body term whenever it is expressed only as a function of the positions of the three bodies, which would seem to invalidate the conceptual advantages of the equations. A solution to this problem has recently been presented (Micha, 1971, 1972), which may be simply described for three hydrogen atoms. A pair of ground-state hydrogens... 

The Faddeev-Watson equations are suitable to the study of permutational symmetry for identical nuclei. This has been done (Micha, 1974) for the three cases in which (1) C = B (2) C = A" and (3) B = A and C = A", to obtain transition amplitudes for direct, atom-exchange and dissociative processes. Nuclear spin variables were included, and amplitudes were found by successively reexpressing symmetrized amplitudes in terms of unsymmetrized ones, reducing nuclear-spin dependences and uncoupling the equations required for calculations. For example in case (2), the terms in the total wavefunction... 

Results from the data compilation of Yaws and co-workers (44,52) were selected. Data for heat of vaporization were correlated using the Watson equation ... 

For the DIPPR project (5), data for heat of vaporization were correlated using a modified Watson equation with extended terms in the exponent ... 

The data compilation of Yaws and co-workers (52) was selected for heat of vaporization for temperatures ranging from melting point to critical point. The Watson equation, Equation (1-2), was used for correlation of the data as a function of temperature. Reliability of results is good with errors of about 1-5% or less. 

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