{"term":{"id":"01456","doi":"10.1351\/goldbook.C01456","code":"C01456","status":"current","longtitle":"IUPAC Gold Book - current distribution","title":"current distribution","termversion":"2.0.2","lastupdated":"2008-10-07","definitions":[{"id":"1","text":"The ratio of current density at a point X on an interface to the average current density (jx\/j) is called the relative local current density. The current distribution is described by the function jx\/j = f(x) (or more generally, jx\/j = f(x,y,z) where x or (x,y,z) are the coordinates of the points of the electrode-solution interface. The primary current distribution is that which establishes itself when the influence of overpotential is negligible. The secondary current distribution is that which establishes itself when the influence of the overpotential cannot be neglected but concentration overpotential is negligible. The secondary distribution is often described in terms of dimensionless numbers of the form where Wa = (κ\/l).(dη\/dj) is the conductivity of the solution, dη\/dj the slope of the overpotential-current curve under the above conditions and l a characteristic length of the system, for instance the radius of a disc electrode. Wa is the Wagner number. It is a quantity which determines the throwing power and characterizes the equalizing influence of overpotential on the current distribution. In electroplating the throwing power is qualitatively defined as 'the ability of a solution to deposit metal uniformly upon a cathode of irregular shape'. The tertiary current distribution is that which establishes itself when the influence of the overpotential (including concentration overpotential) cannot be neglected.","links":[{"title":"current density","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/C01452"},{"title":"interface","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/I03082"},{"title":"average current density","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/A00539"},{"title":"relative local current density","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/R05268"},{"title":"primary current distribution","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/P04828"},{"title":"overpotential","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/O04358"},{"title":"secondary current distribution","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/S05516"},{"title":"concentration overpotential","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/C01230"},{"title":"conductivity","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/C01245"},{"title":"Wagner number","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/W06652"},{"title":"throwing power","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/T06370"},{"title":"cathode","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/C00905"},{"title":"tertiary current distribution","type":"internal","url":"https:\/\/goldbook.iupac.org\/terms\/view\/T06281"}],"math":[{"alttext":"jx\/j","latex":"\\frac{j_{\\text{x}}}{j}"},{"alttext":"jx\/j = f(x)","latex":"\\frac{j_{\\text{x}}}{j} = f(x)"},{"alttext":"jx\/j = f(x,y,z)","latex":"\\frac{j_{\\text{x}}}{j} = f(x,\\,y,\\,z)"},{"alttext":"x","latex":"x"},{"type":"symbol","alttext":"(x,y,z)","latex":"(x,\\,y,\\,z)"},{"alttext":"Wa = (κ\/l).(dη\/dj)","latex":"\\mathrm{Wa}=\\frac{\\kappa }{l}\\ \\frac{\\mathrm{d}\\eta }{\\mathrm{d}j}"},{"alttext":"κ","latex":"\\kappa "},{"alttext":"dη\/dj","latex":"\\frac{\\text{d}\\eta }{\\text{d}j}"},{"alttext":"l","latex":"l"},{"alttext":"Wa","latex":"\\mathrm{Wa}"}],"sources":["PAC, 1981, 53, 1827. 'Nomenclature for transport phenomena in electrolytic systems' on page 1836 (https:\/\/doi.org\/10.1351\/pac198153101827)"]}],"links":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/C01456\/html","json":"https:\/\/goldbook.iupac.org\/terms\/view\/C01456\/json","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/C01456\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/C01456\/plain","pdf":"https:\/\/goldbook.iupac.org\/terms\/view\/C01456\/pdf"},"citation":"Citation: 'current distribution' in IUPAC Compendium of Chemical Terminology, 3rd ed. International Union of Pure and Applied Chemistry; 2006. Online version 3.0.1, 2019. 10.1351\/goldbook.C01456","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2024-03-01T20:37:22+00:00"}}