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.
- ↑ Krieg, Brian J.. In Viv o Predictive Dissolution: Transport Analysis of the CO 2 , Bicarbonate in Vivo Buffer System. Journal of Pharmaceutical Sciences 103 (11) (2014). p. 3473–3490. doi:10.1002/jps.24108.
- ↑ Skoog, Douglas A.. Fundamentals of analytical chemistry (2014). Belmont, CA. p. 200. ISBN 978-0-495-55828-6. OCLC 824171785.