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The principle can be illustrated by taking the indicator to be a simple acid, HA, which dissociates into H + and A −. HA ⇌ H + + A −. The value of the acid dissociation constant, pK a, must be known. The molar absorbances, ε HA and ε A − of the two species HA and A − at wavelengths λ x and λ y must also
For example, the acid may be acetic acid and the salt may be sodium acetate. The Henderson–Hasselbalch equation relates the pH of a solution containing a mixture of the two components to the acid dissociation constant, K a of the acid, and the concentrations of the species in solution. [6]
In chemistry, acid value (AV, acid number, neutralization number or acidity) is a number used to quantify the acidity of a given chemical substance.It is the quantity of base (usually potassium hydroxide (KOH)), expressed as milligrams of KOH required to neutralize the acidic constituents in 1 gram of a sample.
[1] [2] As water is an excellent solvent and is also naturally abundant, it is a ubiquitous solvent in chemistry. Since water is frequently used as the solvent in experiments, the word solution refers to an aqueous solution, unless the solvent is specified. [3] [4] A non-aqueous solution is a solution in which the solvent is a liquid, but is ...
"Glacial acetic acid" is a name for water-free acetic acid. Similar to the German name "Eisessig" ("ice vinegar"), the name comes from the solid ice-like crystals that form with agitation, slightly below room temperature at 16.6 °C (61.9 °F). Acetic acid can never be truly water-free in an atmosphere that contains water, so the presence of 0. ...
In practice, the mixture can be created by dissolving the acid in water, and adding the requisite amount of strong acid or base. When the p K a and analytical concentration of the acid are known, the extent of dissociation and pH of a solution of a monoprotic acid can be easily calculated using an ICE table .
The term "spirit vinegar" is sometimes reserved for the stronger variety (5% to 24% [36] acetic acid) made from sugar cane or chemically produced acetic acid. [37] To be called "spirit vinegar", the product must come from an agricultural source and must be made by "double fermentation".
For buffers in acid regions, the pH may be adjusted to a desired value by adding a strong acid such as hydrochloric acid to the particular buffering agent. For alkaline buffers, a strong base such as sodium hydroxide may be added. Alternatively, a buffer mixture can be made from a mixture of an acid and its conjugate base.