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On the other hand, if a chemical is a weak acid its conjugate base will not necessarily be strong. Consider that ethanoate, the conjugate base of ethanoic acid, has a base splitting constant (Kb) of about 5.6 × 10 −10, making it a weak base. In order for a species to have a strong conjugate base it has to be a very weak acid, like water.
Acid strength is the tendency of an acid, symbolised by the chemical formula, to dissociate into a proton, +, and an anion, .The dissociation or ionization of a strong acid in solution is effectively complete, except in its most concentrated solutions.
In water, measurable pK a values range from about −2 for a strong acid to about 12 for a very weak acid (or strong base). A buffer solution of a desired pH can be prepared as a mixture of a weak acid and its conjugate base. In practice, the mixture can be created by dissolving the acid in water, and adding the requisite amount of strong acid ...
Other strong non-nucleophilic bases are sodium hydride and potassium hydride. These compounds are dense, salt-like materials that are insoluble and operate by surface reactions. Some reagents are of high basicity (pK a of conjugate acid around 17) but of modest but not
For example, deprotonation of an alcohol forms the negatively charged alkoxide, which is a much stronger nucleophile. To determine whether or not a given base will be sufficient to deprotonate a specific acid, compare the conjugate base with the original base. A conjugate base is formed when the acid is deprotonated by the base.
For example, the pK a value of acetic acid is 4.8, while ethanol has a pK a of 16. Hence acetic acid is a much stronger acid than ethanol. This in turn means that for equimolar solutions of a carboxylic acid or an alcohol in water, the carboxylic acid would have a much lower pH. [1]: 263–7
The most common Lewis bases are anions. The strength of Lewis basicity correlates with the pK a of the parent acid: acids with high pK a 's give good Lewis bases. As usual, a weaker acid has a stronger conjugate base. Examples of Lewis bases based on the general definition of electron pair donor include: simple anions, such as H − and F −
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids , whose acidity is associated with their carboxyl group –COOH. Sulfonic acids , containing the group –SO 2 OH, are relatively stronger acids.