Advance discussion of acids bases
A second part is devoted to the subject of
conjugation of acids and bases.
The relationship between the acidic constant Ka,
basic constant Kb, and the constant of autoionization of
water, Kw will be discussed. The relationship is useful for
weak acids and bases.
Skills to develop
Acids and bases are also powerful concepts used to characterize substances. The concepts can and has been extended to much wider applications. For these reason, there are at least three definitions for each of acid and base. These definitions are given at different times to expand the concepts of acids and bases. This is why we do not even define acids and bases in this section.
Let us take a look how the concepts of acid and base are expanded over time. Acids and bases are related, and the relationship is called conjugation. An acid has a conjugate base and vice versa.
Less than 40 years later, in 1923, Bronsted, Lowry and Lewis wanted to expand the concepts of acids and bases so that a wider area of chemistry can be understood using the same principle.
|H+ + OH- |
|HA + B|
-> A + HB
|Electrophil||Nucleophil||E + :Nu -> E:Nu|
Lewis definitions are more general than Bronsted-Lowry's definitions, they are now widely accepted and practiced. The more general definitions for acids and bases allow us to discuss more chemical reactions as acid-base reactions.
The table lists conjugate acid-base pairs for your reference so that you can figure out the strategy of identifying them. Furthermore, for an acid or base, you should be able to give its conjugate base or acid.