Basic solution, definition

NH4)2S04 definitely could not be used in cleaning materials since it produces an acidic solution, not a basic solution. Also, Na2S04 cannot be used either since S042 is an extremely weak base (has a very small Ab). 

Investigations of the equilibria obtaining in solution have provided information concerning the stoichiometry and stability of the species formed when the beryllium ion is hydrolyzed. Although the identification of the minor species can never be regarded as definitive, there is little doubt that the principal species are Be2(OH)3+ and Be3(OH)3+ in acid solutions and Be(OH)3 and Be(OH)r in strongly basic solutions. Further support for these conclusions is provided by some crystal structures. The structure of [Be3(0H)3(H20)6]... 

Differentiation of tautomers by the use of UV spectra has not been too rewarding. Thus whereas hypoxanthine almost certainly exists as the lactam form (13) as indicated by IR and other spectral studies, its UV absorption spectrum (Amax 249 nm, pH 5.6) is similar to that of 6-methoxypurine (Amax 252 nm, pH 5.2), a derivative of the lactim form of hypoxanthine, and l,7-dimethyl-6-oxo-l(if),6(if)-purine (43) (B-73MI40902), a definite lactam derivative. On the other hand, the UV spectrum of 8-oxo-7(H),8(/7)-purine (44) is closer to that of its 7- and 9-monomethyl and 7,9-dimethyl (oxo or lactam) derivatives than to 8-methoxypurine (45) (B-73MI40902) implying the oxo structure. Even in basic solutions where the lactim structure is expected, the results may be difficult to interpret. Thus the spectrum of the anion of hypoxanthine is similar to that of the neutral species of adenine, (Amax 258 and 260 nm, respectively) whereas this is not true of the 2- and 8-oxopurines when compared with the corresponding aminopurines. 

Figure 15.11 shows x-ray diffraction (XRD) profiles of ceria powders produced by precipitation. The XRD data for the synthesized particles show characteristics of Ce02 with a typical fluorite stracture. Since the starting cerium salt was Ce(N03)3, it required the oxidation of Ce + to Ce + in the solution. In this system, there is a possible cause for this oxidation. According to the Lewis definition of acids and bases, Ce is a Lewis base and Ce + is a Lewis acid. Basic solution therefore favors Ce compared with Ce . The crystallite size was calculated from the Scherrer formula ... 

In acidic solutions the H3O+ concentration is always greater than the OR- concentration. We should not conclude that acidic solutions contain no OR- ions. Rather, the [OR-] is always less than 1.0 X IQ- M in such solutions. The reverse is true for basic solutions, in which the [OH-] is always greater than 1.0 X 10 M. By definition, neutral aqueous solutions at 25°C are solutions in which [H3O+] = [OR-] = 1.0 X 10- M. 

A major problem with Arrhenius s acid-base theory is that some substances, like ammonia, produce basic solutions and react with acids, but do not contain hydroxide ions. In 1923 Johannes Bronsted, a Danish chemist, and Thomas Lowry, an English chemist, independently proposed a new way to define acids and bases. An acid donates hydrogen ions (also called a proton donor) a base accepts hydrogen ions (also called a proton acceptor). These definitions not only explain all the acids and bases covered by Arrhenius s theory, they also explain the basicity of ammonia and ions such as carbonate, and phosphate, P04 ... 

The Bronsted-Lowry definitions also explain why carbonate salts such as sodium carbonate (washing soda) dissolve in water to give basic solutions. Carbonate ion removes a hydrogen ion from a water molecule, which leaves behind a hydroxide ion ... 

Isopolymolybdates. When a basic solution containing only M0O4- and alkali-metal or ammonium ions is acidified, the molybdate ions condense in definite steps to form a series of polymolybdate ions. At the pH where condensation begins for both CrO and M0O4- the species M03(OH) are formed mo02-+h+- Mo03(OH)-... 

There are definite limitations to the cydodextrins. The presence of many hydroxyl groups makes the problem of selective functionalization difficult. Moreover, the glycoside linkages are only stable in neutral or basic solution, thereby restricting somewhat the chemical reactions than can be studied. 

Because many acidic and basic solutions occur in nature, observations about acids and bases date back hundreds of years. One of the most important observations is that a solution cannot be both acidic and basic at the same time. Mixing an acid and a base leads to a reaction known as neutralization, in which the resulting solution is neither acidic nor basic. To understand the origins of this neutralization, we might start with the definitions of acid and base. Acid solutions contain H3O ions, and bases contain OH ions. So for a solution to be both an acid and a base simultaneously, it would need to contain both of these species. Looking at those ions, it should be easy to see why this is not feasible. Hydronium ions and hydroxide ions combine readily to form water ... 

Acids are described by their properties (sour taste, ability to dissolve metals, ability to neutralize bases, ability to turn litmus red) (13.1, 13.2) or by their molecular definitions (H+ producer, proton donor) (13.4). Bases are described by their properties (bitter taste, slippery feel, ability to neutralize acids, ability to turn litmus blue) (13.3) or by their molecular definition (0H producer, proton acceptor) (13.4). Acids and bases are either strong (complete dissociation in water) or weak (partial dissociation in water) (13.5). The acidity or basicity of a solution is specified using the pH scale in which pH = 7 specifies a neutral solution pH > 7, a basic solution and pH < 7, an acidic solution (13.6-13.8). 

Definitions. Define and illustrate briefly (a) pH, (b) acidic solution, (c) basic solution, (d) conservation condition, (e) electrical neutrality condition, (f) common-ion efiect, (g) bufiFer solution, (h) solubility product. 

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