The "hydrogen ion" and the "electron" in these examples are respectively called the "reaction units."
By this definition, the number of equivalents of a given ion in a solution is equal to the number of moles of that ion multiplied by its valence. For example, consider a solution of 1 mole of NaCl and 1 mole of CaCl2. The solution has 1 mole or 1 equiv Na+, 1 mole or 2 equiv Ca2+, and 3 mole or 3 equiv Cl−.
An earlier definition, used especially for chemical elements, holds that an equivalent is the amount of a substance that will react with 1 g (0.035 oz) of hydrogen, 8 g (0.28 oz) of oxygen, or 35.5 g (1.25 oz) of chlorine—or that will displace any of the three.[8]
In medicine and biochemistryedit
In biological systems, reactions often happen on small scales, involving small amounts of substances, so those substances are routinely described in terms of milliequivalents (symbol: officially mequiv; unofficially but often mEq[2] or meq), the prefix milli- denoting a factor of one thousandth (10−3). Very often, the measure is used in terms of milliequivalents of solute per litre of solution (or milliNormal, where meq/L = mN). This is especially common for measurement of compounds in biological fluids; for instance, the healthy level of potassium in the blood of a human is defined between 3.5 and 5.0 mEq/L.
A certain amount of univalent ions provides the same amount of equivalents while the same amount of divalent ions provides twice the amount of equivalents. For example, 1 mmol (0.001 mol) of Na+ is equal to 1 meq, while 1 mmol of Ca2+ is equal to 2 meq.
Referencesedit
^"CAS Standard Abbreviations & Acronyms". www.cas.org. Retrieved 2017-07-26.
^ abAmerican Medical Association, "14.12: Units of Measure", AMA Manual of Style, retrieved 2019-10-23.
^ ab"Potassium Supplement (Oral Route, Parenteral Route) Proper Use - Mayo Clinic". www.mayoclinic.org.
^ ab"Potassium - assessment of suggestd maximum limits in food supplements". VKM Report. 16 December 2016.
^ ab"Proposed maximum levels for the addition of potassium to foods including food supplements" (PDF). German Federal Institute for Risk Assessment. (PDF) from the original on 2022-12-12.
A dictionary of units of measurement 2018-10-06 at the Wayback Machine
January 01, 1970
equivalent, chemistry, confused, with, electrochemical, equivalent, equivalent, symbol, officially, equiv, unofficially, often, amount, substance, that, reacts, with, equivalent, arbitrary, amount, typically, mole, another, substance, given, chemical, reaction. Not to be confused with Electrochemical equivalent An equivalent symbol officially equiv 1 unofficially but often Eq 2 is the amount of a substance that reacts with or is equivalent to an arbitrary amount typically one mole of another substance in a given chemical reaction It is an archaic Quantity that was used in chemistry and the biological sciences see Equivalent weight In history The mass of an equivalent is called its equivalent weight Contents 1 Formula 1 1 Common examples 1 1 1 mEq to milligram 1 1 2 Milligram to mEq 2 Formal definition 3 In medicine and biochemistry 4 References 5 External linksFormula editThe formula from milligrams mg to milli equivalent mEq and back is as follows mg mEq mg V M W mEq mg mEq M W V displaystyle begin aligned text mg to text mEq amp quad text mg times frac V MW 4pt text mEq to text mg amp quad text mEq times frac MW V end aligned nbsp where V is the valence and MW is the molecular weight For elemental compounds mg mEq element mass mg mass fraction V M V displaystyle text mg to text mEq quad frac text element mass mg text mass fraction times frac V MV nbsp Common examples edit mEq to milligram edit Compound Chemical formula Molecular weight MW Valencies V Sample Reference Elemental mEq Elemental mEq to compound weight Potassium reference K 39 098 g mol 1 K 20 mEq potassium 20 39 098 1 782 mg Potassium citrate monohydrate C6H7K3O8 324 41 g mol 3 K Liquid potassium citrate gluconate therapy for adults and teenagers taken two to four times a day 3 20 mEq potassium 20 324 3 2160 mg Potassium gluconate anhydrous C6H11KO7 234 245 g mol 1 K Liquid potassium citrate gluconate therapy for adults and teenagers taken two to four times a day 3 20 mEq potassium 20 234 245 1 4685 mg Milligram to mEq edit Compound Chemical formula Molecular weight MW Elemental mass fraction Valencies V Sample Reference Weight Compound weight to elemental mEq Potassium reference K 39 098 g mol 100 1 K 3000 mg 3000 1 39 098 77 mEq K Potassium citrate monohydrate C6H7K3O8 324 41 g mol 36 16 3 K Tolerable DRI for potassium dietary supplements 4 5 8 3 g 3000 0 3616 8296 3 324 41 77 mEq K Potassium gluconate anhydrous C6H11KO7 234 245 g mol 16 69 1 K Tolerable DRI for potassium dietary supplements 4 5 18 g 3000 0 1669 17975 1 234 245 77 mEq K Formal definition editIn a more formal definition the equivalent is the amount of a substance needed to do one of the following react with or supply one mole of hydrogen ions H in an acid base reaction react with or supply one mole of electrons in a redox reaction 6 7 The hydrogen ion and the electron in these examples are respectively called the reaction units By this definition the number of equivalents of a given ion in a solution is equal to the number of moles of that ion multiplied by its valence For example consider a solution of 1 mole of NaCl and 1 mole of CaCl2 The solution has 1 mole or 1 equiv Na 1 mole or 2 equiv Ca2 and 3 mole or 3 equiv Cl An earlier definition used especially for chemical elements holds that an equivalent is the amount of a substance that will react with 1 g 0 035 oz of hydrogen 8 g 0 28 oz of oxygen or 35 5 g 1 25 oz of chlorine or that will displace any of the three 8 In medicine and biochemistry editIn biological systems reactions often happen on small scales involving small amounts of substances so those substances are routinely described in terms of milliequivalents symbol officially mequiv unofficially but often mEq 2 or meq the prefix milli denoting a factor of one thousandth 10 3 Very often the measure is used in terms of milliequivalents of solute per litre of solution or milliNormal where meq L mN This is especially common for measurement of compounds in biological fluids for instance the healthy level of potassium in the blood of a human is defined between 3 5 and 5 0 mEq L A certain amount of univalent ions provides the same amount of equivalents while the same amount of divalent ions provides twice the amount of equivalents For example 1 mmol 0 001 mol of Na is equal to 1 meq while 1 mmol of Ca2 is equal to 2 meq References edit CAS Standard Abbreviations amp Acronyms www cas org Retrieved 2017 07 26 a b American Medical Association 14 12 Units of Measure AMA Manual of Style retrieved 2019 10 23 a b Potassium Supplement Oral Route Parenteral Route Proper Use Mayo Clinic www mayoclinic org a b Potassium assessment of suggestd maximum limits in food supplements VKM Report 16 December 2016 a b Proposed maximum levels for the addition of potassium to foods including food supplements PDF German Federal Institute for Risk Assessment Archived PDF from the original on 2022 12 12 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 equivalent entity doi 10 1351 goldbook E02192 International Union of Pure and Applied Chemistry 1998 Compendium of Analytical Nomenclature definitive rules 1997 3rd ed Oxford Blackwell Science ISBN 0 86542 6155 section 6 3 Chapter 6 3 The use of the equivalence concept PDF Archived from the original PDF on July 26 2011 Retrieved 2009 05 10 Atome Grand dictionnaire universel du XIXe siecle in French vol 1 Paris Pierre Larousse 1866 pp 868 73External links editA dictionary of units of measurement Archived 2018 10 06 at the Wayback Machine Retrieved from https en wikipedia org w index php title Equivalent chemistry amp oldid 1218808335, wikipedia, wiki, book, books, library,
