Bases in aqueous solutions

Quantities, Wiley-Interscience, New York, 1976 D. D. Perrin, Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution, 2d ed., Pergamon Press, 1982. 

D.D. Perrin, Dissociation Constants of Organic Bases in Aqueous Solution, Butterworths, London, 1965 and Supplement 1972. 

The problem of determining K independently of measurement of Hq is the principal issue to be faced in establishing the Hq scale for a series of acidic solutions. What is done is to measure K for some base in aqueous solution where Hq pH. This base can than be used to find the Hq of a somewhat more acidic solution. The K of a second, somewhat weaker base is then determined in the more acidic solution. This second base can then be used to extend Hq into a still more acidic solution. The process is continued by using a... 

In this chapter we first identified acids and bases in aqueous solution by investigating the proper-... 

The Bronsted-Lowry theory of acids and bases referred to in Section 10.7 can be applied equally well to reactions occurring during acid-base titrations in non-aqueous solvents. This is because their approach considers an acid as any substance which will tend to donate a proton, and a base as a substance which will accept a proton. Substances which give poor end points due to being weak acids or bases in aqueous solution will frequently give far more satisfactory end points when titrations are carried out in non-aqueous media. An additional advantage is that many substances which are insoluble in water are sufficiently soluble in organic solvents to permit their titration in these non-aqueous media. 

As for acids, the strength of a base depends on the solvent a base that is strong in water may be weak in another solvent and vice versa. The common strong bases in aqueous solution are listed in Table J.l. 

The value of Kb tells us how far the reaction proceeds to the right. The smaller the value of Kh the weaker is the ability of the base to accept a proton. Table 10.2 lists the basicity constants of some weak bases in aqueous solution. 

Write the proton transfer equilibria for the following bases in aqueous solution and identify the conjugate acid-base pairs in each one (a) CIS- (b) NH2NH2, hydrazine (c) C032- ... 

The acidity of a base is the number of hydroxy ions formed per molecule of the base in aqueous solution. It may also be considered as the number of H+ ions that can be accepted by one molecule of the base. Thus, NaOH and KOH are monoacid bases, Ca(OH)2 and Mg(OH)2 are diacid bases, and Al(OH)3 and Fe(OH)3 are triacid bases. 

III. Comparison of Behavior of Lewis Acids and Bases in Aqueous Solution and in... 

The EA/CA ratio was proposed as a measure of hardness of the Lewis acid, and EB/CB as hardness of the Lewis base in aqueous solution (17). It now seems that the E/C ratio is not a measure of hardness in the sense in which Pearson (5,5a) defined hardness. Rather, the E/C ratio for a Lewis acid or base is a measure of the tendency to ionicity in the M-L bonds formed. The EAICA ratio should rather be called IA, and the EbICb ratio IB, the tendency to ionic bonding in forming the M-L bond. Acids and bases in Tables I and II are placed in order of increasing tendency towards ionicity in the M-L bond, according to the E/C ratios IA and 7b. A justification for this interpretation is that the order of IA values for metal ions in aqueous solution strongly resembles the order of hardness derived by Pearson (19) from enthalpies of complex forma-... 

The anhydrous petrolatum base may be made more miscible with water through the use of an anhydrous liquid lanolin derivative. Drugs can be incorporated into such a base in aqueous solution if desired. Poly-oxyl 40 stearate and polyethylene glycol 300 are used in an anti-infective ointment to solubilize the active principle in the base so that the ointment can be sterilized by aseptic filtration. The cosmetic-type bases, such as the oil-in-water (o/w) emulsion bases popular in dermatology, should not be used in the eye, nor should liquid emulsions, owing to the ocular irritation produced by the soaps and surfactants used to form the emulsion. 

Hall, N. F. Sprinkle, M. R., Relations between the structure and strength of certain organic bases in aqueous solution, J. Am. Chem. Soc. 54, 3469-3485 (1932). 

The above treatment of moderately dilute acids and dibasic acids can be used for analogous cases of bases. Table 1.7 lists examples of dissociation constants of bases in aqueous solutions. 

Hare PM, Crespo-Hernandez CE, Kohler B (2007) Internal conversion to the electronic ground state occurs via two distinct pathways for the pyrimidine bases in aqueous solution. Proc Natl Acad Sci... 

Mechanisms, of proton transfer between oxygen and nitrogen acids and bases in aqueous solutions, 22, 113... 

Fig. 2 Variation of forward (fcf)and reverse (kr) rate coefficients with ApK for proton transfer from acetic acid to various bases in aqueous solution at 293K and ionic strength 1.0mol dm-3...

Amenate derivatives that do not carry substitutents at the exocydic nitrogen atom undergo a ring-opening reaction to nitroso cyanohydrazines 127 upon treatment with bases in aqueous solutions [151]. 

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