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Acids and bases may be found almost everywhere. Lemons and dairy products contain citric acid, similar to the lactic acid found in yoghurt. Bases include household cleaning agents such as bleach and ammonia. A significant component of chemistry is the study of acidic and basic chemical reactions. Several hypotheses exist to describe what makes up acid and bases theories.
The French scientist Antoine Lavoisier gave the first scientific definition of acid in the eighteenth century, which was accepted by the scientific community. He hypothesised that acids included oxygen, despite being unaware of the dual composition of acids such as hydrochloric acid (HCl). A far more exact definition of acids and bases has been developed throughout the years.
Bases
Bases are those substances that have a bitter taste, are odourless, turn red litmus blue when exposed to acid, have a pH greater than 7, and become less alkaline when exposed to base. These are more violent and less reactive than acids, although they are reactive. To name a few examples: LiOH (Lithium hydroxide), NaOH (Sodium hydroxide), KOH (potassium hydroxide), etc.
However, these are the typical characteristics of acids and bases; it is not true for every acid and base.
What are the three acid-base theories?
The Arrhenius theory (Swedish chemist Svante Arrhenius was awarded the Nobel Prize in Chemistry for this) in 1903.
The Lewis theory, or electron-pair theory, in 1923.
The Brønsted-Lowry theory, or proton donor theory, in 1923.
These are the three theories that identify a single characteristic that defines an acid and a base. These theories have their pros and weaknesses; each may be effective in particular situations.
Lewis acids-bases theories
Brønsted-Lowry concept
Arrhenius acids-bases theories
Lewis acids-bases theories
This hypothesis has the widest possible range of acids and bases in terms of theories. A Lewis acid accepts electron pairs, while a Lewis base donates them. Protons and hydrogens are not included in this category, which allows for a wider range of compounds. If you look at the Lewis hypothesis, it claims that a lewis acid and a lewis base share a pair of electrons.
Lewis bases theories
Lewis bases are substances capable of donating electrons that are classified as bases. Depending on the context, they are frequently referred to as “electron-rich species” or “nucleophiles,” depending on the context.
Features of Lewis bases theories
The Lewis base-electron-pair donor. They all can contribute electrons; however, all Lewis bases theories cannot provide electrons to other ions (F, Cl, Br, I). Lewis bases include ions, molecules, and atoms with just one pair of electrons. Lewis bases, such as benzene, ethene, and others in the electron-rich system, are also included in this category. The electron density may be adjusted to boost the Lewis base’s strength.
Brønsted-Lowry concept
An acid capable of donating a proton to someone else is referred to as a Brønsted-Lowry acid following the Brønsted-Lowry Theory of acidification. Brønsted-Lowry bases are defined as those capable of accepting a proton from a source other than themselves.
Definition of acids-bases theories was offered by a Danish chemist Johannes Nicolaus Brønsted and a British scientist named Thomas Martin Lowry. Their definition was based on the ability of a chemical to either donate or take protons, respectively.
The Brønsted-Lowry theory of acid and bases is known as the Proton Theory of Acid and Base. In this theory, a hydrogen atom is often thought of as a proton that has lost all of its electrons and has transformed into a positively charged hydrogen ion (indicated by the symbol H+).
According to Brønsted-Lowry bases theories:
Acid is a Hydrogen ion (Proton) donor
The base is a Hydrogen ion (Proton) acceptor
Conclusion
The acids and bases theories discussed in this chapter have provided us with all the fundamental knowledge about acids and bases. Our discussion in this chapter included every aspect of acid-base chemistry, from its origins in Arrhenius theory to its development in Brønsted-Lowry theory to its development in Lewis acids-bases theories. Acids and bases are very important in the field of medicine. Because of this notion, it is now possible to treat illnesses more effectively with better medications, thanks to a more nuanced knowledge of acids and bases. For example, the rise in the concentration of hydrogen ions in the human blood leads to an increase in acidity, which causes the body to become feeble. As a result, the body should maintain its alkaline balance by digesting foods that create alkali in the body, which will help to counteract the acidity.
