Theories of Acid and Base
There are various concepts of acid and base and some of them are
- Lewis’s Concept of Acids and Bases
- Arrhenius’s Concept of Acids and Bases
- Bronsted Lowry’s Theory of Acids and Bases
They are discussed below in the article
Lewis Concept of Acids and Bases
According to Lewis, “Acids are the substance which accepts an electron pair and are electrophilic in nature i.e. they have incomplete valance orbital which can accept electron pairs.”
Examples of Lewis acids are, Cu2+, Fe3+, etc.
Similarly,” Bases are the substance which has an electron pair in their outermost valence shell and they can easily donate those electron pair, they are nucleophilic in nature.”
Examples of Lewis bases are Cl–, NH3, etc.
The Lewis definition of an acid states that it is a species that has a vacant orbital and therefore, has the ability to accept an electron pair.
Arrhenius Concept of Acids and Bases
Arrhenius’s concept of acid and bases is the basic concept which explains the concept of acid and base.
According to Arrhenius, “Acids are the substance that on dissolving in water releases H+ ions.” These H+ ions combine with H2O molecules to form hydronium ions (H3O+).
Examples of acids are HCl, H2SO4, etc.
Similarly, “Bases are the substance that on dissolving in water releases OH– ions.”
Examples of bases are NaOH, Ca(OH)2, etc.
Bronsted Lowry Theory of Acids and Bases
Another theory which explains the definition of Acid and Base is the Bronsted-Lowry theory of acid and base which says that,
“Acids are the substance which is categorised as protons (or H+) acceptors whereas bases are the substance which accepts protons (or H+) from the water.”
The limitation of this theory is that it is unable to explain the acidic behaviour of BF3 and AlCl3 as they lack to give protons in their aqueous solution and still are considered to be acidic.
Acids and Bases
An acid is a substance that is capable of donating a proton (hydrogen ion) to another substance. A base is a molecule able to donate OH- ion/strong>. Acidic substances are usually identified by their sour taste.
Acids have a sour taste and are corrosive i.e. exposure to acid on human skin can cause blisters. Some examples of acids are HCl, H2SO4, and others.
Let’s learn more about acids and bases, their properties, theories, and others in this article.
Table of Content
- What are Acids?
- What are Bases?
- Acid Bases Titration
- pH of Acid and Base
- Difference between Acids and Bases
- Acid-Base Reaction
- Acid-Base Indicator Definition
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