Amphoterism
A chemical compound is amphoteric if it can act as both an acid and a base.[1] Amphoteric compounds are essential to life; not only water, but also bicarbonate as part of buffer solutions used to control acidity in the body.[2]
Example
Water is amphoteric.[3] A strong acid (such as hydrochloric acid) will react with water to produce a hydronium ion and the acid's conjugate base (such as the chloride ion). In this reaction, water is a base:
- H
2O + HCl → H
3O+
+ Cl−
Reactions with water as an acid are more complicated. Many compounds known as "strong base" do not react with water at all: instead, they are salts of hydroxide that dissolve in water. Hydroxide is the conjugate base of water, so the two will not react; a stronger base is needed to cause an acid-base reaction. With the right base (such as the methoxide ion), a reaction will occur that makes hydroxide and the conjugate acid (such as methanol).
- H
2O + CH
3O−
→ OH−
+ CH
3OH
Related pages
- Amphoteric oxide, oxygen compounds that show amphoterism
References
- ↑ International Union of Pure and Applied Chemistry. "Amphoteric". Compendium of Chemical Terminology Internet edition.
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Skoog, Douglas A.; West, Donald M.; Holler, F. James; Crouch, Stanley R. (2014). Fundamentals of analytical chemistry (Ninth ed.). Belmont, CA. p. 200. ISBN 978-0-495-55828-6. OCLC 824171785.