Hayduk-Laudie equation

Diffusion coefficients may be estimated using the Wilke-Chang equation (Danckwerts, 1970), the Sutherland-Einstein equation (Gobas et al., 1986), or the Hayduk-Laudie equation (Tucker and Nelken, 1982), which state that Dw values decrease with the molar volume (Vm) to the power 0.3 to 0.6. Alternatively, the semi-empirical Worch relation may be used (Worch, 1993), which predicts diffusion coefficients to decrease with increasing molar mass to the power of 0.53. These four equations yield very similar D estimates (factor of 1.2 difference). Using the estimates from the most commonly used Hayduk-Laudie equation... 

Hayduk-Laudie They presented a simple correlation for the infinite dilution diffusion coefficients of nonelectrolytes in water. It has about the same accuracy as the Wilke-Chang equation (about 5.9 percent). There is no explicit temperature dependence, but the 1.14 exponent on I compensates for the absence of T in the numerator. That exponent was misprinted (as 1.4) in the original article and has been reproduced elsewhere erroneously. 

Siddiqi-Lucas These authors examined 658 aqueous liqiiid mixtures in an empirical study. They found an average absolute deviation of 19.7 percent. In contrast, the Wilke-Chang equation gave 35.0 percent and the Hayduk-Laudie correlation gave 30.4 percent. 

Die next parameter we need is the diffusion coefficient Df of hydrogen peroxide in water. Here, we can assume the approximate value of 10 9 m2/s. However, this coefficient will be needed further in this example for the determination of the effective solid-phase diffusion coefficient, in a calculation that is extremely sensitive to the value of the liquid-phase diffusion coefficient. For this reason, coefficient should be evaluated with as much accuracy as possible. The diffusion coefficient of solutes in dilute aqueous solutions can be evaluated using the Hayduk and Laudie equation (see eq. (1.26) in Appendix I) ... 

For the determination of diffusion coefficient of solutes (except from salts and ions) in water and dilute solutions (<10%) the Hayduk and Laudie equation is used (Lyman et al., 1990 Perry and Green, 1999) ... 

Very few experimentally determined diffusivities of organic substances in water are available in the documented literature. If experimentally determined diffusivity values are not available, Hayduk and Laudie (1974) recommend the following equation for estimating this parameter ... 

As was the case for T>,a, the equations derived from the pure physical concepts are usually not the best numerical approximations of a given quantity, although they show which properties should enter into an empirical relationship. Othmer and Thakar (1953) derived the following expression with coefficients modified slightly by Hayduk and Laudie (1974) ... 

As for equation (1.18), Hayduk and Laudie, 1974 (35) tested the reliability of this equation for different aqueous solutions and they concluded that a revised equation of the following form should relate diffusion data best... 

For diffusion in dilute aqueous solutions the following equation is provided by Hayduk and Laudie ... 

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