KB value

Solvent name CAS Registry Number Common name (trade name) Empirical formula KB" value Solubihty parameter 5,... 

Hydrocarbon Solvents. Most hydrocarbon solvents are mixtures. Few commercial hydrocarbon solvents are single compounds. Toluene is an exception. Hydrocarbon solvents are usually purchased and suppHed on specification. The most important specification properties are distillation range, solvency as expressed by aniline cloud poiat and Kauri-Butanol (KB) value, specific gravity, and dash poiat. Composition requirements such as aromatic content and benzene concentration are also important ia many appHcations. 

In practice, Kb values are not often used. Instead, the most convenient way to measure the basicity of an amine (RNH2) is to look at the acidify of the corresponding ammonium ion (RNH3+). 

Click Coached Problems for a self-study module on determining Ke and Kb values. 

Short-form measures of activity—potency ratios for agonists, apparent KB values (pA2, IC50)—for... 

The resulting fit is shown in Figure 12.2c. The regression is linear with a slope not significantly different from unity (slope = 0.95 0.1). The intercept yields the KB value in this case, 1 pM. 

Referring to each amine shown in Table 11.5, as the temperature increases so the dissociation constant Kb decreases (although ratios between amines may change). Conversely, as temperature decreases, so Kb increases. Generally, because we are concerned with relatively high temperatures, the Kb value is likely to be lower than shown in some published tables, and so more product will be required than possibly anticipated. 

Consequently, amines with high Kb values require lower concentrations than do low Kb materials to raise pH levels. Nevertheless, volatility, DR, thermal stability, and other factors also need to be taken into account. Inevitably, amine selection is a compromise between these various functional properties. 

This reaction is simple and qualitative36 37 the diamine can be both an aromatic and an aliphatic diamine. With this method, even star-shaped PAs have been synthesized.37 Solution polymerization from acid chlorides and aliphatic diamines is more difficult due to the strong basicity of the aliphatic amine groups. Acid binders which have been used with aliphatic diamines are the tertiary amines with high kb values these include dimethylbenzylamine and diisopropylethylamine.4 38... 

Hydrochloric acid has the highest Ka on this list and is, therefore, the strongest acid listed. Lithium hydroxide is the strongest base listed. Because Ka and Kb values are often very large or very small numbers, chemists have converted them into an easier form called pKa and pKb. 

In initial studies with /3-CD it was noted that values of ka vary in inverse proportion to the inhibition constant, Kt, suggesting that PI is bound in the CD cavity in the transition state (Tee and Hoeven, 1989). Therefore, the Pi-mediated reaction is more reasonably viewed as being between the ester and the PI-CD complex. The third-order processes in (21) and (24) are kinetically equivalent (k2 = k.JKs = kJKy), and so kb values are easily found from k.t. Such values of kb show some variation with structure but they are quite similar for different Pis and not very different from k2 for the reaction of the CD with pNPA For example, for pNPA reacting with 15 different alcohol /3-CD complexes values of kb span the range 10-95 m 1 s l (Table A5.14), close to k2 = 83m-1s-1 for the reaction of pNPA with /3-CD alone. Similar behaviour was observed for other Pis (Table A5.14) and for aCD (Table A5.13), for which k2 = 26 m-1 s 1. 

Kauri-butanol number A measurement of solvent strength for hydrocarbon solvents the higher the Kauri-butanol (KB) value, the stronger the solvency the test method (ASTM D1133) is based on the principle that Kauri resin is readily soluble in butyl alcohol but not in hydrocarbon solvents and that the resin solution will tolerate only a certain amount of dilution and is reflected as cloudiness when the resin starts to come out of solution solvents such as toluene can be added in a greater amount (and thus have a higher KB value) than weaker solvents such as hexane. 

The results for KB using the different methods are not directly comparable. Kb values resulting from assumption of a 1 1 interaction are consecutive constants, whereas values calculated in the second case represent the product of all equilibria. Nevertheless the strength of interactions tends to be the same for each drug investigated. 

The solvency of a petroleum product is a function of the aromatic content. The Kauri-Butanol KB value is used to describe the solvency power of a petroleum product. There are both advantages and disadvantages associated with high fuel or oil KB values. 

Paraffins function poorly as a solvent for some organic compounds. This fact can have various consequences. For example, gums, deposits, and fuel degradation products will not be dissolved or held in solution by high-paraffin-content fuels. As a result, gums and degradation products will fall from solution and settle onto fuel system parts such as storage tank bottoms and fuel system lines. The KB value for selected petroleum products is provided in TABLE 5-4. 

Diesel fuel and kerosene alone are not effective solvents for use in solubilizing most WCMs for low-temperature application. The low KB value of diesel fuel and kerosene makes these fuels ineffective at holding the WCM in solution for extended periods of time at low temperatures. Stratification and separation of the WCM from solution can lead to application problems such as filter plugging and inaccurate WCM treatment. 

Kauri-Butanol (KB) Value A measure of the relative solvent power of a hydrocarbon the higher the KB value, the greater the effect of the hydrocarbon as a solvent. 

Solvent Type Hashpoint OF TCC+ Boiling Point, °F Kb Value Evaporation Rate... 

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