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|Section2= }} In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogen carbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula HCO3−. Bicarbonate serves a crucial biochemical role in the physiological pH buffering system.〔(【引用サイトリンク】 publisher = Biology.arizona.edu )〕 The term "bicarbonate" was coined in 1814 by the English chemist William Hyde Wollaston.〔William Hyde Wollaston (1814) "A synoptic scale of chemical equivalents," ''Philosophical Transactions of the Royal Society'', 104 : 1-22. (On page 11 ), Wollaston coins the term "bicarbonate": "The next question that occurs relates to the composition of this crystallized carbonate of potash, which I am induced to call bi-carbonate of potash, for the purpose of marking more decidedly the distinction between this salt and that which is commonly called a subcarbonate, and in order to refer at once to the double dose of carbonic acid contained in it."〕 The prefix "bi" in "bicarbonate" comes from an outdated naming system and is based on the observation that there is two times as much carbonate (CO3) per sodium ion in sodium bicarbonate (NaHCO3) and other bicarbonates as in sodium carbonate (Na2CO3) and other carbonates.〔http://www.newton.dep.anl.gov/askasci/chem99/chem99492.htm〕 ==Chemical properties== The bicarbonate ion (hydrogencarbonate ion) is an anion with the empirical formula HCO3− and a molecular mass of 61.01 daltons; it consists of one central carbon atom surrounded by three oxygen atoms in a trigonal planar arrangement, with a hydrogen atom attached to one of the oxygens. It is isoelectronic with nitric acid . The bicarbonate ion carries a negative one formal charge and is the conjugate base of carbonic acid ; at the same time, it is the conjugate acid of , the carbonate ion, as shown by these equilibrium reactions: :CO32− + 2 H2O HCO3− + H2O + OH− H2CO3 +2 OH− :H2CO3 + 2 H2O HCO3− + H3O+ + H2O CO32− + 2 H3O+. A bicarbonate salt forms when a positively charged ion attaches to the negatively charged oxygen atoms of the ion, forming an ionic compound. Many bicarbonates are soluble in water at standard temperature and pressure, in particular sodium bicarbonate contributes to total dissolved solids, a common parameter for assessing water quality. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「bicarbonate」の詳細全文を読む スポンサード リンク
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