Buffering capacity, defined

Tam, K. Y. BUFM AKE A computer program to calculate the compositions of buffers of defined buffer capacity and ionic strength for ultra-violet spectrophotometry, Comp. Chem. 23, 415 119 (1999). 

Define buffer solution, conjugate acid, conjugate base, conjugate acid-base pair, buffer capacity, and buffer region. 

The extent to which the pH of a solution is buffered against additions or removals of protons is measured by the solution s pH buffer capacity. This is defined as the amount of strong acid or base required to produce unit change in pH. The buffering depends on the transfer of protons between donors and acceptors, i.e. Bronsted acids and bases, which form conjugate acid-base pairs. The pH buffer capacity of a solution is calculated from the buffer capacities of the individual acid-base pairs present. 

Consider a generic acid-base pair HX-X representing the various acid-base pairs in a solution. The pH buffer capacity of the HX-X pair is defined as... 

The buffer capacity (/J) of a solution is defined as the number of moles of strong base needed to increase the pan of 1 liter of the solution by one unit, and can be expressed by... 

Buffer capacity, P, is a measure of how well a solution resists changes in pH when strong acid or base is added. Buffer capacity is defined as... 

The buffer capacity may be considered as defined for the incremental addition of a constituent to a closed system at equilibrium—e.g., adding a strong acid to a carbonate solution, C02 to a water solution in equilibrium with calcite, a strong acid to a sea water solution in equilibrium with both kaolinite and muscovite, etc. In general,... 

The buffer capacity j3, defined as the moles of acid or base necessary to change the pH of one liter of solution by one unit, is given by... 

The quality of the product is defined in terms of the d.e., pH, buffer capacity, and content of dry substance, and of certain special specifications related to specific uses. An example of such a specification is the degree of inversion of sucrose that is attained when a hard candy is made by boiling a mixture of sucrose and the specimen of com syrup almost to dryness under very carefully controlled test-conditions. If... 

The ability of a buffer to resist changes in pH is referred to as the "buffer capacity." Buffer capacity" can be defined.in two ways (1) the number of moles per liter of or OH required to cause a given change in pH (e.g., 1 unit), or (2) the pH change that occurs upon addition of a given amount of H" or OH (e.g., 1 mole/liter). The first definition is better because it can be applied to buffers of any concentration. 

The effectiveness of a buffer in reducing changes in pH is expressed as the buffer capacity, /3. The buffer capacity is defined by the ratio... 

The buffer capacity is defined as the number of moles per litre of strong monobasic acid or base required to produce an increase or decrease of one pH unit in the solution. When the concentrations of salt and acid are equal, the log term in the Henderson-Hasselbalch equation becomes the logarithm of 1, which equals 0. To move the pH of the buffer solution by one unit of pH will require the Henderson-Hasselbalch equation to become... 

The buffer capacity is defined as the number of moles of strong alkali added divided by change in pH observed. 

Boundary potential, E, The resultant of two potentials that develop at the surfaces of a glass membrane electrode. Bronsted-Lowry acids and bases An acid of this type is defined as a proton donor and a base as a proton acceptor the loss of a proton by an acid results in the formation of a species that is a potential proton acceptor, or conjugate base of the parent acid. Buffer capacity The number of moles of strong acid (or strong base) needed to alter the pH of 1.00 L of a buffer solution by 1.00 unit. 

Acidity and alkalinity titrations determine the total capacity of natural waters to consume strong bases or acids as measured to specified pH values defined by the endpoints of titrations. Of more interest for many purposes is the ability of a water or water-rock system to resist pH change when mixed with a more acid or alkaline water or rock. This system property is called its buffer capacity. Buffer capacity is important in aqueous/environmental studies for reasons that include ... 

The concept of pH buffer capacity as a measure of resistance to pH change can be applied to our thinking about the buffering of environmental systems with respect to their concentrations of other substances, including electrons (as defined by redox potential, cf. Nightingale 1958) or contaminant trace metals (cf. Pankow 1991). 

Here we restrict ourselves to pH buffers. Van Slyke (1922) defined pH buffers as substances which by their presence in solution increase the amount of acid or alkali which must be added to cause a unit change in pH. In aqueous solutions pH buffering is especially due to the interaction of weak acids and bases and their salts with water. The quantification of this effect, the buffer capacity or buffer index, is by definition... 

In other words, the pH for the maximum buffer capacity of a weak acid is defined by pH = ipK , and the value of is a function only of Q, the total acid-species concentration. The same reasoning applies to the maximum buffer capacity of weak bases. 

Define buffer capacity and explain how the buffer capacity of a water relates to the titration curve for its acidity and alkalinity. 

The units of OXC and RDC, as defined, are eq/L or meq/L. This makes OXC comparable to acidity and alkalinity, which are also given in eq/L or meq/L (Chap. 5). The pH buffer capacity measures the resistance of a system to pH change at a given pH, upon addition of a strong acid or base (Chap. 5). The concept of redox capacity, as proposed by Nightingale (1958) and defined above, is... 

In a number of cases it is of advantage to express buffer intensity as molar buffer capacity -Km, which may be defined as... 

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