Alkalinity terminology

Like FeO and MgO, both primitive and evolved arc lavas extend to CaO contents much lower than in primitive and evolved MORE glasses, and andesites are the low CaO end-member among primitive lavas. It is ironic that low CaO is one of the characteristics of these, end-member calc-alkaline lavas this suggests that the tholeiitic versus calc-alkaline terminology should be changed. 

By the treatment of Cross and Bevan cellulose, or cellulose isolated by some other purification procedure, with 17.5% sodium hydroxide under carefully controlled conditions, and then carefully washing, a fibrous product is obtained which is termed a-cellulose. As previously indicated, Cross and Bevan used this procedure for determining the purity of cellulose preparations. This product upon further similar treatments continues to lose weight, indicating the empirical nature of the treatment and terminology. Upon acidif3ring the alkaline filtrate a precipitate is formed. This fraction is known as /3-celIulose. The alkali-soluble extract which remains in solution after acidification of the solution is termed -y-cellulose. Since continued extraction of a-cellulose with caustic causes the formation of increasing amounts of /3-and y-cellulose, the incomplete removal of these fractions in one operation or the conversion of o-cellulose into 0- and -y-cellulose is indicated. In practice... 

Scheme Effective charge map for the alkaline hydrolysis of aryl acetate esters. Both Bronsted and Hammett terminologies are illustrated but this makes no difference to the magnitude of either Leffler s a or the effective charges...

Although the definitions of humic acid and of other fractions were initially based on extraction of soil with alkaline reagents, the same terminology is used when the extractants are neutral, acidic, or organic. In these cases the term humin means not extracted, humic acid means soluble in the ex-... 

A Terminology Problem There are theoretically several different alkalinity endpoints, each with its own name, and there is also some confusion in the usage of carbonate alkalinity and total alkalinity . In this book we discuss the only endpoint in common use (pH 4.3).7 We use total alkalinity to refer to the general case in which all ions which affect the titration are included, and carbonate alkalinity to refer to any titration or corrected titration in which only carbonate and/or bicarbonate ions are neutralized. 

It is difficult to define precisely the term aqueous silica sols and thereby contrast them with other forms of silica (colloidal silica, colloidal quartz, pyrogenic silica, and so forth). Bulk chemical distinctions are not very useful. The definition chosen here follows Iler s terminology (I). Aqueous silica sols are characteristically composed of spherical particles nucleated and grown by alkaline hydrolysis of sodium silicate solutions. They are often monodisperse systems and have particle diameters in the range 1-100 nm (density, —2.2 g/cm3) that lead to sols that vary from optically transparent to opalescent. 

Alkali metal, see Terminology, Metals, p.242 Alkaline earth metal, see Terminology, Metals, p.242... 

The terminology used for mechanisms in this section is based on the Ingold system (reference 112). The lUPAC nomenclature (reference 161) for alkaline hydrolyses of esters is as follows The BacI mechanism is Dm + + A hDh- The Bac2 reaction is termed An + Dn + A hDh. For... 

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