Volatility increase

The volatility of ammonia can be significantely affected by high concentrations of dissolved ions in the liquid phase. In sodium acetate the volatility increases by a factor of 1.9 at 25 wt % of salt. In sodium hydroxide the volatility is enhanced to a lesser degree with an increase of 1.25 at 22.5 wt % NaOH. Both electrolytes produce ions with only one electronic charge, but their effects on the volatility of ammonia are significantly different. Thus the effects of various ionic components must be studied individually in order to determine their effect on the volatility of NH3. 

The transport of disulfoton from water to air can occur due to volatilization. Compounds with a Henry s law constant (H) of <10 atm-m /mol volatilize slowly from water (Thomas 1990). Therefore, disulfoton, with an H value of 2.17x10" atm-m /mol (Domine et al. 1992), will volatilize slowly from water. The rate of volatilization increases as the water temperature and ambient air flow rate increases and decreases as the rate of adsorption on sediment and suspended solids increases (Dragan and Carpov 1987). The estimated gas- exchange half-life for disulfoton volatilization from the Rhine River at an average depth of 5 meters at 11 °C was 900 days (Wanner et al. ] 989). The estimated volatilization half-life of an aqueous suspension of microcapsules containing disulfoton at 20 °C with still air was >90 days (Dragan and Carpov 1987). 

Since relative volatilities increase in most distillation systems as pressure decreases, the optimum operation would be to minimize the pressure at all times. One way to do this is to just completely open the control valve on the cooling water. The pressure would then float up and down as cooling water temperatures changed. 

A volatile, paraffin fuel will deposit the least amount of coke. Decreasing volatility increases coke deposition but has little effect on smoke. Increasing aromaticity increases both coke and smoke. Minor components have no effect within the maximum permitted by fuel specifications. 

Branched-chain alkanes do not exhibit the same smooth gradation of physical properties as do the continuous-chain alkanes. Usually there is too great a variation in molecular structure for regularities to be apparent. Nevertheless, in any one set of isomeric hydrocarbons, volatility increases with increased branching. This can be seen from the data in Table 4-2, which lists the physical properties of the five hexane isomers. The most striking feature of the data is the 19° difference between the boiling points of hexane and 2,2-dimethylbutane. 

A significant fraction of UFP may be volatile, particularly in particles smaller than 50 nm [24, 25], Volatility increased with decreasing distance to a major freeway [24]. In a study in four apartments near a US freeway, I/O ratios were highest for particles of about 100 nm, decreased up to about 20 nm and then increased again for particles smaller than 20 nm [25]. The pattern below 20 nm did not agree with previous theory (Sect. 3). A potential explanation is that upon infiltration losses may occur of volatile components, resulting in a shift of the particle size distribution towards particles less than 20 nm [25],... 

E. Wasserman (The DuPont Company, U.S.A.). When you talk about the possible phases of something like C60 (is it a gas, a liquid or a low density liquid of high compressibility), we really have to compare it with another phase which may be accessible under the same temperature and pressure conditions. In many such cases, some of the features of C60 are due to intermolecular interactions, in some of the more condensed phases, rather than to individual molecular properties that you were concentrating on. For example, the very strong tenacity of one C60 molecule to bond to another, as well as to incorporate solvent molecules in the interstitial spaces, depends critically on how well they seem to fit together, as well as to the intrinsic forces that may be found in smaller molecules. We find that if you have small degrees of substitution of C6, for example, alkyl groups, the volatility increases dramatically. 

The hydride complexes of actinides usually contain a coligand, such as, for example, OR, dmpe, or Cp, and can be monomeric or oligomeric. Thus, the borohydrides An(BH4)4 produced according to (5.68) are polymeric (An = Th, U) or monomeric (An = Np, Pu), whereas the An(BH3Me)4 are all monomeric. Their volatility increases from Th to Pu, whereas their stability goes in the opposite direction [282] ... 

Lockett (12) and King (126) noted some theoretical sense in O Connell s correlation. Higher viscosity usually implies lower dif-fusivity, and therefore, greater liquid phase resistance and lower efficiency (12). Higher relative volatility increases the significance of the liquid phase resistance [Eq. (7.13)), thus reducing efficiency (126), Lockett expressed the O Connell plot in equation form... 

Solvent Loading. The solvent circulation rate is a function of the reflux ratio in the primary tower and the liquid-phase concentration of the solvent. For a given solvent selectivity, as the solvent concentration rises, the propane-propylene relative volatility increases and hence the required reflux rate falls. The increased relative volatility results in a decreased number of equilibrium stages required for the desired separation. Figure 4 shows the effect of solvent concentration on the number... 

Figure 3, taken from the data of Dobroserdov (2), gives another example of the substantial effect that a salt, even at reasonably moderate concentration, can have in certain systems. The key components are again ethanol and water, but here the salt is calcium chloride, present at a constant concentration of 10 grams/100 ml of alcohol-water solution. The azeotrope has been completely eliminated, and relative volatility increased substantially. 

This process, also utilized for the synthesis of deuterides , allows small quantities of pure hydrides to be obtained in the laboratory. The reaction sp>eed, low for Na, a metal of low volatility, increases with the T, of the metal. This can be increased without dissociating the hydride layer at the metal surface here (the hydride formed on the upper wall of the tube is mixed with metal) by increasing the P to 2 or 3 atm. 

The effectiveness of mass selective detection in the SIM(MIM) mode and selected wavelength chromatograms (SWC) in FT-IR-detection depends on efficient sample clean-up. In raw extracts the risk of co-eluting substances which remain indiscri-minative from chiral volatiles increases with the complexity of flavouring and fragrance extracts to be analyzed. 

Ethanol has a strong effect on the wine bouquet as the odour threshold of many volatiles increases in its presence, e.g. the threshold of ethyl 2- and 3-methylbutanoate by a factor of 100 [106]. 

Froth systems higher pressure slightly increases efficiency Low relative volatility increases efficiency Minimal effect... 

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