The Basic Dissociation Constant of Valine

Quantum mechanics investigation of acid dissociation constant of carboxylic acids in aqueous solution

According to the Bronsted definition, any compound which has a hydrogen atom is an acid, since itmay be lost as a proton. A thermodynamical cycle is proposed to calculate absolute pKa values forBronsted acids in aqueous solution. The equilibrium of dissociation of a Bronsted acid depends onthe interaction of the acid and its conjugate base with solvent molecules. There fore the pKa valuedepends...

Spectrophotometric determination of the dissociation constant of ribonuclease S'.

Dissociation Constant in Nitrogen Fixation by Azotobacter

6 Dodge originally used "A" and "a" to designate the two sex types in Neurospora crassa. Lindegren later substituted the symbols "+" and "-" for these. Because of the desirability of using the symbol + for the normal allele of a gene and also to designate a positive experimental result, we prefer Dodge's original designations. 4 Neither conversion of pimelic acid to p-aminobenzoic acid by the n...

The Apparent Dissociation Constant of Glycine Ethyl Ester.*

According to the classical theory of the dissociation of weak electrolytes, the amino acids show much lower basic and acidic dissociation constants than would be expected from a comparison with other weak acids and bases. In order to explain this anomaly, Adams (1) originally suggested that an ampholyte must necessarily exist almost entirely as an “inner salt.” Bjerrum (2) extended this idea wi...

Application of Chemometrics in determination of the effects of ionic and non-ionic surfactants on ac-id dissociation constant (pKa) of Meloxicam using spectrophotometric method

The purpose of this study was to determine the acid dissociation constants (pKa) of meloxicam in the presence of various surfactants including sodium lauryl sulfate (SLS) as an anionic surfactant, cetyltrimethylammonium bromide (CTAB) as a cationic surfactant and Triton® TX-100 (TX-100) as a non-ionic surfactant in different pre-determined concentrations. The related pKa was determined spec...