Ammonium hydroxide 594615 223685612 2008-07-05T07:16:32Z Puppy8800 5404759 iw {{main|ammonia}} '''Ammonium hydroxide'''(NH<sub>3</sub>[aq]), also known as '''ammonia water''', '''aqua ammonia''', or '''aqueous ammonia''', is a solution of [[ammonia]] in water. Technically, the use of the term "ammonium hydroxide" is incorrect because such a chemical compound can not be isolated. However, this term does give a fair description of how an ammonia solution behaves, and is commonly used even by scientists and engineers. ==Chemistry== In aqueous solution, ammonia deprotonates some small fraction of the water to give [[ammonium]] and [[hydroxide]] according to the following [[chemical equilibrium|equilibrium]]: :NH<sub>3</sub> + H<sub>2</sub>O <math>\rightleftharpoons</math> NH<sub>4</sub><sup>+</sup> + OH<sup>−</sup> With a base ionization constant (''K''<sub>b</sub>) of 1.8×10<sup>−5</sup>, in a 1M [[ammonia]] solution about 0.42% of the ammonia will gain protons to become [[ammonium]] ions (equivalent to a pH of 11.63). Aqueous ammonia is used in traditional qualitative inorganic analysis. Like many amines, it gives a deep blue coloration with copper(II) solutions. Ammonia solution can dissolve silver residues, such as that formed from [[Tollens' reagent]]. Solutions of ammonium can also dissolve reactive metals such as zinc, with the liberation of hydrogen gas. When ammonium hydroxide is mixed with dilute [[hydrogen peroxide]] in the presence of a metal ion, such as Cu<sup>2+</sup>, the peroxide will undergo rapid decomposition. ==See also== * [[Common chemicals]] * [[Conjugate acid]] ==External links== *[http://www.airgasspecialtyproducts.com/UserFiles/laroche/PDF/AAPhysical.pdf Ammonium hydroxide physical properties] [[Category:Ammonium compounds]] [[Category:Bases]] [[da:Ammoniakvand]] [[de:Ammoniumhydroxid]] [[es:Hidróxido de amonio]] [[fr:Ammoniaque]] [[ko:암모니아수]] [[hu:Ammónium-hidroxid]] [[nl:Ammonia]] [[pl:Woda amoniakalna]] [[pt:Hidróxido de amônio]] [[ru:Гидроксид аммония]] [[sk:Čpavok]] [[sv:Ammoniumhydroxid]] [[zh:氨水]] [[zh-yue:氨水]]