Acid-base theoiy

At about the same time that Brpnsted proposed his acid-base theoiy, Lewis put forth a broader theory. A base in the Lewis theory is the same as in the Brpnsted one. 

Goldbeig Fundamentals of I 19. Acid-Base Theoiy Chemistiy, Fifth Edition... 

The content of a curriculum must be functional when dealing with societal activities necessary chemical concepts, skills and attitudes with respect to macro-micro thinking must be included. This can be derived from representative authentic tasks. The content of the curriculum should be considered as a chemical toolbox. The traditional content of the present chemistry curriculum, such as the stmcture of atoms, ionic theoiy, fundamental acid-base calculations, are not necessarily part of the chemical toolbox when addressing chemical and technological tasks. The validity of the toolbox (philosophical substmcture) is determined by the representative practices and tasks related to chemistry (cf need-to-know principle in context-based approaches). 

According to Lowiy and Bronsted s theoiy— an acid is a substance capable of yielding a proton (hydrogen ion), while a base is a substance capable of accepting a proton . Thus, a complementary relationship exists between an acid and a base that may be expressed in a generalized fashion as below ... 

The Arrhenius definition was an important contribution to understanding many acids and bases, but it does not explain why a compound such as ammonia (NH3) neutralizes acids, even though it has no hydroxide ion in its molecular formula. In Section 1-13 we discuss a more versatile theoiy of acids and bases that will include ammonia and a wider variety of organic acids and bases. 

The SC descriptions of the electronic mechanisms of the three six-electron pericycUc gas-phase reactions discussed in this paper (namely, the Diels-Alder reaction between butadiene and ethene [11], the 1,3-dipolar cycloaddition of fulminic acid to ethyne [12], and the disrotatory electrocychc ring-opening of cyclohexadiene) take the theory much beyond the HMO and RHF levels employed in the formulation of the most popular MO-based treatments ofpericyclic reactions, including the Woodward-Hoffmann rules [1,2], Fukui s frontier orbital theoiy [3] and the Dewar-Zimmerman model [4-6]. The SC wavefunction maintains near-CASSCF quality throughout the range of reaction coordinate studied for each reaction but, in contrast to its CASSCF counterpart, it is veiy much easier to interpret and to visualize directly. 

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