Search results
Results from the WOW.Com Content Network
Metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides. Many metals (such as zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Aluminium oxide (Al 2 O 3) is an example of an amphoteric oxide. Amphoterism depends on the oxidation states of the oxide.
The Brønsted–Lowry theory (also called proton theory of acids and bases [1]) is an acid–base reaction theory which was first developed by Johannes Nicolaus Brønsted and Thomas Martin Lowry independently in 1923.
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, Brønsted–Lowry acid–base theory.
The essence of Brønsted–Lowry theory is that an acid only exists as such in relation to a base, and vice versa. Water is amphoteric as it can act as an acid or as a base. In the image shown at the right one molecule of H2O acts as a base and gains H+ to become H3O+ while the other acts as an acid and loses H+ to become OH−.
Bases and acids are seen as chemical opposites because the effect of an acid is to increase the hydronium (H 3 O +) concentration in water, whereas bases reduce this concentration. A reaction between aqueous solutions of an acid and a base is called neutralization , producing a solution of water and a salt in which the salt separates into its ...
In 1923, he recognized that acid–base reactions involved the transfer of a proton, from the acid (proton donor) to the base (proton acceptor). [8] Almost simultaneously and independently, the British chemist Martin Lowry arrived at the same conclusion, thus the name Brønsted–Lowry acid–base theory. [9]
Such acids are used in cracking. Many solid Brønsted acids are also employed industrially, including sulfonated polystyrene, sulfonated carbon, [1] [2] solid phosphoric acid, niobic acid, and heteropolyoxometallates. [3] A particularly large scale application is alkylation, e.g., the combination of benzene and ethylene to give ethylbenzene.
One use of conjugate acids and bases lies in buffering systems, which include a buffer solution. 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.