Dissociation constant nitrogen-containing

Prins reaction, heteropolyacid catalysis, 41 156 Probe molecules, 42 119 acidic dissociation constant, 38 210 NMR solid acidity studies, 42 139-140 acylium ions, 42 139, 160 aldehydes, 42 162-163 alkyl carbenium ions, 42 154-157 allyl cation, 42 143-144 ammonia, 42 172-174 arenium ions, 42 150-154 carbonium ions, 42 157-160 chalcogenenonium ions, 42 161-162 cyclopentenyl cations, 42 140-143 indanyl cations, 42 144-147 ketones, 42 162,163-165 nitrogen-containing compounds, 42 165-170... 

Table 8.3 lists the base dissociation constants for several weak bases at 25°C. Nitrogen-containing compounds are Bronsted-Lowry bases, because the lone pair of electrons on a nitrogen atom can bond with H+ from water. The steps for solving problems that involve weak bases are similar to the steps you learned for solving problems that involve weak acids. 

Most plant alkaloids are derivatives of tertiary amines, while others contain primary, secondary or quarternary nitrogen. The basicity of individual alkaloids varies considerably, depending on which of the four types is represented. The pK values (dissociation constants) lie in the range of 10-12 for very weak bases (e.g. purines), of 7-10 for weak bases (e.g. Cinchona alkaloids) anti of 3-7 for medium-strength bases (e.g. Opium alkaloidvSh... 

This book contains values of dissociation constants for organic bases In aqueous solution. The bases are arranged under the headings aliphatic, allcyclic, aromatic, heterocyclic, natural products, dyes and indicators, substances lacking a basic nitrogen atom, and miscellaneous. Accompanying the data entry for each base is the temperature, method of measurement, formula, assessment of the measurement, and the appropriate reference. There are 3790 data entries in this book. Also see item [73]. 

Dissociation constants of o-glucuronic acid, o-galacturonic acid, their methyl ethers, and the corresponding 4,5-unsaturated derivatives have been measured and rationalized in terms of various operating electronic factors. Observations on details of the reduction of uronic acid esters to hexopyrano-sides, on nitrogen-containing derivatives, and on branched-chain uronic acids are made in Chapters 3, 9, and 13, respectively. 

Because the reaction is endothermic, the equilibrium constant increases with increasing temperature, but still, even at 3000° and ordinary pressures, there is no appreciable dissociation. The great strength of the NsN bond is principally responsible for the chemical inertness of N2 and for the fact that most simple nitrogen compounds are endothermic even though they may contain strong bonds. Thus E(NssN) 6E(N—N) whereas E(C C) 2.5E(C—C). 

Suppose the reaction occurs in a flowing gas mixture of methane and air. Assume that the pressure is constant at Ibar, the reactant mixture is at a temperature of 298.15K and has stoichiometric proportions of methane and oxygen, and the reaction goes to completion with no dissociation. For the quantity of gaseous product mixture containing 1 mol CO2,2 mol H2O, and the nitrogen and other substances remaining from the air, you may use the approximate formula C (P) = a + bT, where the coefficients have the values a = 297.0 JK and b = 8.520 X 10 JK . Solve Eq. 11.6.1 for T2 to estimate the flame temperature to the nearest kelvin. 

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