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Strong. Superbases. Non-nucleophilic. Weak. v. t. e. A weak base is a base that, upon dissolution in water, does not dissociate completely, so that the resulting aqueous solution contains only a small proportion of hydroxide ions and the concerned basic radical, and a large proportion of undissociated molecules of the base.
A strong base is a basic chemical compound that can remove a proton (H +) from (or deprotonate) a molecule of even a very weak acid (such as water) in an acid–base reaction. Common examples of strong bases include hydroxides of alkali metals and alkaline earth metals, like NaOH and Ca (OH) 2, respectively.
A Lewis base is an atomic or molecular species where the highest occupied molecular orbital (HOMO) is highly localized. Typical Lewis bases are conventional amines such as ammonia and alkyl amines. Other common Lewis bases include pyridine and its derivatives. Some of the main classes of Lewis bases are.
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.
Superbases. Non-nucleophilic. Weak. v. t. e. As the name suggests, a non-nucleophilic base is a sterically hindered organic base that is a poor nucleophile. Normal bases are also nucleophiles, but often chemists seek the proton-removing ability of a base without any other functions. Typical non-nucleophilic bases are bulky, such that protons ...
For example, acetic acid is a weak acid which has a = 1.75 x 10 −5. Its conjugate base is the acetate ion with K b = 10 −14 /K a = 5.7 x 10 −10 (from the relationship K a × K b = 10 −14), which certainly does not correspond to a strong base. The conjugate of a weak acid is often a weak base and vice versa.
In chemistry, an acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH via titration. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example ...
In and of themselves, pH indicators are usually weak acids or weak bases. The general reaction scheme of acidic pH indicators in aqueous solutions can be formulated as: HInd (aq) + H 2 O (l) ⇌ H 3 O + (aq) + Ind − (aq) where, "HInd" is the acidic form and "Ind −" is the conjugate base of the indicator. Vice versa for basic pH indicators ...