Base neutralizing capacity

Base neutralizing capacity = -Acid neutralizing capacity... 

Acidity. Acidity is the base-neutralizing capacity of a sample of water. It is determined by titration of the sample with standard base to pH 8.3... 

Hydrogen ion regulation in natural waters is provided by numerous homogeneous and heterogeneous buffer systems. It is important to distinguish in these systems between intensity factors (pH) and capacity factors (e.g., the total acid- or base-neutralizing capacity). The buffer intensity is found to be an implicit function of both these factors. In this chapter, we discuss acid-base equilibria primarily from a general and didactic point of view. In Chapter 4 we address ourselves more specifically to the dissolved carbonate system. 

In the same monoprotic acid-base system, the base-neutralizing capacity with respect to the reference level (/ = 1) of a NaA solution (proton condition [HA] -I- [H ] = [OH ]) is defined by... 

The base-neutralizing capacity of the phosphoric acid system with reference to the equivalence point, / = 2 (solution of Na2HP04 with the proton condition 2[H3P04] -h [H2P04 ] -h [H ] = [POj ] -h [OH" ]), is given by... 

Figure 4.7. Conservative quantities alkalinity and acidity as acid-neutralizing and base-neutralizing capacity. These parameters can be determined by acidimetric and alkalimetric titration to the appropriate end points. The equations given below define the various capacity factors of an aqueous carbonate system rigorously. If the solution contains protolytic systems other than that of aqueous carbonate, these equations have to be corrected for example, in the presence of borate one has to add [B(OH).Tl to the right-hand side of equation 3 and IH3BO3] to the right-hand side of equation 6.

In general terms, alkalinity is the Acid Neutralizing Capacity of a solution, that is, the quantity of acid required to neutralize the solution. The acidity is similarly the Base Neutralizing Capacity , the quantity of base required to neutralize the acidity of a solution. Alkalinity and acidity are determined by titrating a sample of solution with an acid (such as HC1) or a base (such as NaOH) of known concentration. However, the variety of ways in which these simple concepts can be defined and interpreted has led to much confusion. Several modeling programs now do not allow input of acidity or alkalinity, as such, partly because of this confusion. However, others do, and in any case users will still have to deal with these concepts if they appear in their analyses. 

Acid or base neutralizing capacity is that quantity of a strong monobasic acid or monoacidic base in mmol which is used by 1 litre of water to achieve... 

Werner Stumm (see, for example, Stumm and Morgan 1981, 1995, Stumm 1987, Sigg and Stumm 1996, Zobrist 1987) introduced the acidity as a base neutralizing capacity (BNC), corresponding to the equivalent of all acids within the solution, titrated to a given reference point ... 

Titration with alkalies is one of the earliest and simplest methods used to determine the nature and amount of surface acidic groups on carbons. However, the standard conditions under which comparable results can be obtained have been realized during the last few decades. It is now recognized that the base neutralization capacity of a carbon should be determined after degassing the sample at 150°C so as to free it from any physically adsorbed gases and vapors. The carbon sample is then placed in contact with a 0.1 to 0.2 N alkali solution for 24 to 72 hr. The contact time can be reduced to a few hours if the carbon and the alkali solution are heated under reflux. These conditions are now being followed by many of the investigators. 

Relationship Between Base Neutralization Capacity and COj Evolved on Evacuation of Various Charcoals at 1200°C... 

Bansal et al. " combined desorption and base neutralization techniques for investigating the acidic surface groups on several polymer carbons. The base neutralization capacity using sodium hydroxide was found to be almost exactly equivalent to the amount of CO2 evolved on evacuation in the case of polyvinylidene (PVDC), polyvinyl chloride... 

PVC), and Saran (a copolymer of PVDC and PVC) charcoals but was almost half of the amount of CO2 evolved in the case of polyfurfurylalocbol (PF) and urea fonnolede-loyde (UF) charcoals (Table 1.6). The base neutralization capacity decreased on evacuation, and the decrease at any temperature corresponded to the amount of CO2 evolved at that temperature. Furthermore, the temperature interval over which the drop in base neutralization occurred appears to be the same (Figure 1.8) as the temperature interval over which CO2 was evolved from the carbon sample. 

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