Lux-Flood definition

Hie base (GaO) is an oxide donor and (be add (SiO,) is an oxide acceptor The usefulness of the Lux-Flood definition is mostly limited lo systems such as molten oxides. 

Lux—Flood Definition In contrast to the BrpnstedLowry theory, which emphasizes the proton as the principal species in acid-base reactions, the definition proposed by Lux and extended by Flood describes add-base behavior in terms of the oxide ion. This add-base concept was advanced to treat non protonic systems which were not amenable to the Bipnsted-Lowry definition. For example, in high-temperature inorganic melts, reactions such as the following take place ... 

Lux—Flood Definition In contrast to the Brpnsted-Lowiy theory, which emphasizes the proton as the... 

Effects of Additives. Selected additives to molten nitrate systems offer possibilities of specific acid-base reactions or formation of specific complexes with the various chemical species. Acids and bases are conveniently denoted in oxyanionic molten salt systems by the Lux-Flood definition (18, 19). Acids are defined as compounds capable of removing oxide ions from the melt, while bases are defined as compounds capable of donating oxide ions to the melt. Examples of various acidic and basic species may be found in the general review articles (14, 15,... 

It should be noted that there are some curious interpretations in the literature concerning oxoacidity, which distort to a greater or lesser degree the original definition. For example, Delimarskii and Barchuk [3] give as the Lux definition where a base is a donor of oxide or halide ions. Moreover, at least in the Russian translation of a book [21], the Lux-Flood definition is where an acid is a donor of oxide ions and a base is an acceptor of O2-. Certainly, these definitions are erroneous, as may be seen by reading the original Lux paper [17]. 

Donor-acceptor interactions in ionic media are often deseribed as acid-base interactions according to Lewis and Lux-Flood " definitions. The elassie variant of the former definition considers acids as acceptors of electron pairs and bases as their donors. In modem variant of this definition, acids are the electron pair (or anion) acceptors or cation (proton) donors, bases are the electron pair (anion) donors or cation (proton) acceptors. 

Lux-Flood definition considers bases as donors of oxide-ion, O, its acceptors are Lux acids. 

Find out about the Lux-Flood definition of acids and bases. 

Lux-Flood definition is less common than that by Lewis. It is mainly applicable for ionic melts, oxide-containing glasses, and metallnrgical slags. It defines acids as acceptors of oxide ion (0 ) and its acceptors are referred to as Lux aeids. 

From this scheme it follows that the Lux-Flood definition is a particular case of more common Lewis definition described above. For the quantitative interpretation of interactions with the transfer of, Lux introduces the pO index serving as a measure of basic (acidic) properties of a melt ... 

The data on solubility of CaO and ZnO in the chloride melts permit to follow the effect of the acidic properties of the melt constituent cation on the metal oxide solubilities. The ratio of solubilities in K, Na and Lf-based melts is as follows 1 1.5 15. The total solubilities are discussed and the obtained data are distorted by contribntion of appreciable concentrations of non-dissociated oxide, which is not sensitive to the melt acidity changes. It should be emphasized that, since we do not know the ratios of the ionized fraction to the non-dissociated fraction in the melts studied, we cannot quantitatively estimate the oxoac-idic properties of these melts. The metal oxide dissociation was neglected because studies were conducted in 1923, whereas the Lux-Flood definition was formulated only in 1939. 

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