Lewis's Theory of Acids & Bases

Lewis's theory discusses the interaction between acids and bases.

The Lewis theory examines the nature of chemical bonding, allowing chemists to classify chemical substances and analyze chemical reactions. It is one of several theories about the properties and behavior of acids and bases.

History

The theory originated in 1923, when American chemist Gilbert Newton Lewis proposed a new approach to understanding the water-producing reaction between hydrogen and hydrogen oxide.

Features

The Lewis Theory states that acids accept or pick up electron pairs from other molecules, while bases give or attach electron pairs to other molecules. Substances capable of accepting electron pairs are called Lewis acids, while those capable of donating electron pairs are called Lewis bases.

Identification

Reactions demonstrating Lewis's Theory feature an upward-curving arrow that represents the transfer of an electron pair from the Lewis base to the Lewis acid.

Benefits

Lewis's Theory covers systems with no hydrogen atoms, which were previously excluded by the Bronsted and Arrhenius models. Lewis's theory expands the number of acids and acid-base reactions that chemists work with.

Limitations

The Lewis theory does not take into account the relative strengths of bases and acids. Strength is a measure of the ease with which an acid or base functions of a source of hydrogen or hydroxide ions, respectively, in an aqueous solution.

References

• Chemguide.co.uk: Theories of acids and bases
• Purdue University: The Lewis Definitions of Acids and Bases
• Purdue University: Acids and Bases