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Buffer capacity rises to a local maximum at pH = pK a. The height of this peak depends on the value of pK a. Buffer capacity is negligible when the concentration [HA] of buffering agent is very small and increases with increasing concentration of the buffering agent. [3] Some authors show only this region in graphs of buffer capacity. [2]
Within a rock of a given chemical composition, iron enters minerals based on the bulk chemical composition and the mineral phases which are stable at that temperature and pressure. For instance, at redox conditions more oxidizing than the MH (magnetite-hematite) buffer, at least much of the iron is likely to be present as Fe 3+ and hematite is ...
Tricine is an organic compound that is used in buffer solutions. The name tricine comes from tris and glycine, from which it was derived. [1] It is a white crystalline powder that is moderately soluble in water. It is a zwitterionic amino acid that has a pKa1 value of 2.3 at 25 °C, while its pKa2 at 20 °C is 8.15. Its useful buffering range ...
The following table presents pK a values at 20 °C. Values change by about 0.01 per degree of temperature. [1] [3] Good's original 1966 paper had two older buffers (marked with italics) for comparison. In 1972 Good published a second list with three more buffers, and five more were added in 1980.
In a buffer, a weak acid and its conjugate base (in the form of a salt), or a weak base and its conjugate acid, are used in order to limit the pH change during a titration process. Buffers have both organic and non-organic chemical applications. For example, besides buffers being used in lab processes, human blood acts as a buffer to maintain pH.
In organic chemistry, functionality is often used as a synonym for functional group. For example, a hydroxyl group can also be called a HO-function. [1] [2] Functionalisation means the introduction of functional groups, for example the functionalisation of a surface [3] (e.g. silanization for the specific modification of the adhesion of a surface)
The standard state of a material (pure substance, mixture or solution) is a reference point used to calculate its properties under different conditions.A degree sign (°) or a superscript Plimsoll symbol (⦵) is used to designate a thermodynamic quantity in the standard state, such as change in enthalpy (ΔH°), change in entropy (ΔS°), or change in Gibbs free energy (ΔG°).
In chemistry and biochemistry, the Henderson–Hasselbalch equation = + ([] []) relates the pH of a chemical solution of a weak acid to the numerical value of the acid dissociation constant, K a, of acid and the ratio of the concentrations, [] [] of the acid and its conjugate base in an equilibrium.