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	~~Marvella~~ is ~~what you can contact her but it'~~s ~~not~~ the ~~most female name out there~~. ~~Bookkeeping~~ is ~~her working day occupation now~~. ~~South Dakota~~ is where I'~~ve always been living~~. ~~To collect coins~~ is 1 of ~~the things~~ I ~~adore most~~.<br><br>~~my homepage~~; [http://~~chatmast~~.com/~~index~~.~~php~~?do=/~~BookerSipessk~~/~~info~~/ ~~over the counter std test~~]		The '''ionic strength''' of a solution is a measure of the concentration of ions in that solution. [[Ion]]ic [[Chemical compound\|compound]]s, when dissolved in water, dissociate into [[ions]]. The total [[electrolyte]] concentration in solution will affect important properties such as the dissociation or the solubility of different [[Salt (chemistry)\|salts]]. One of the main characteristics of a solution with dissolved ions is the ionic strength.

			==Quantifying ionic strength==
			The '''ionic strength''', ''I'', of a solution is a function of the [[concentration]] of ''all'' [[ion]]s present in that [[solution]].

			<math>I = \begin{matrix}\frac{1}{2}\end{matrix}\sum_{{\rm i}=1}^{n} c_{\rm i}z_{\rm i}^{2}</math>

			where ''c''<sub>i</sub> is the [[molarity\|molar concentration]] of ion i (M, mol/L), ''z''<sub>i</sub> is the [[Electric charge\|charge]] number of that ion, and the sum is taken over all ions in the solution. For a 1:1 [[electrolyte]] such as [[sodium chloride]], the ionic strength is equal to the concentration, but for [[Magnesium sulfate\|MgSO<sub>4</sub>]] the ionic strength is four times higher. Generally [[multivalency\|multivalent]] ions contribute strongly to the ionic strength.
			===Calculation example===
			For example the ionic strength of a mixed 0.050 M in Na<sub>2</sub>SO<sub>4</sub> and 0.020 M in KCl solution is:

			:''I'' = 1/2 × [(Concentration of Na<sub>2</sub>SO<sub>4</sub> in M × # of Sodium ions × (Charge of Sodium)<sup>2</sup>) + (Concentration of Na<sub>2</sub>SO<sub>4</sub> in M × # of SO<sub>4</sub> ions × (Charge of SO<sub>4</sub>)<sup>2</sup>) + (Concentration of KCl × # of Potassium ions × (Charge of Potassium)<sup>2</sup>) + Concentration of KCl in M × # of Chloride ions × (Charge of Chloride)<sup>2</sup>)]

			:''I'' = 1/2 × [(0.050 M × 2 × (+1)<sup>2</sup>) + (0.050 M × 1 × (−2)<sup>2</sup>) + (0.020 M × 1 × (+1)<sup>2</sup>) + 0.020 M × 1 × (−1)<sup>2</sup>)] = 0.17 M

			==Non-ideal solutions==
			Because in non-[[ideal solution]]s volumes are no longer strictly additive it is often preferable to work with [[molality]] ''b'' (mol/kg{H<sub>2</sub>O}) rather than molarity ''c'' (mol/L). In that case, ionic strength is defined as:

			<math> I = \begin{matrix}\frac{1}{2}\end{matrix}\sum_{{i}=1}^{n} b_{i}z_{i}^{2} </math>

			in which
			:''i'' = ion identification number
			:''z'' = charge of ion

			==Importance==
			The ionic strength plays a central role in the [[Debye-Hückel equation\|Debye–Hückel theory]] that describes the strong deviations from ideality typically encountered in ionic solutions. It is also important for the theory of [[double Layer (interfacial)\|double layer]] and related [[electrokinetic phenomena]] and [[electroacoustic phenomena]] in [[DLVO theory\|colloids]] and other [[heterogeneous]] systems. That is, the Debye length, which is the inverse of the [[Peter Debye\|Debye]] parameter (''κ''), is inversely proportional to the square root of the ionic strength. [[Debye length]] is characteristic of the Double layer thickness. Increasing the concentration or [[valence (chemistry)\|valence]] of the counterions compresses the double layer and increases the electrical potential gradient.

			Media of high ionic strength are used in [[Determination of equilibrium constants\|stability constant determination]] in order to minimize changes, during a titration, in the activity quotient of solutes at lower concentrations. Natural waters such as seawater have a non-zero ionic strength due to the presence of dissolved salts which significantly affects their properties.

			==See also==
			* [[Activity (chemistry)]]
			* [[Activity coefficient]]
			* [[Bromley equation]]
			* [[Double layer (interfacial)]]
			* [[Double layer (electrode)]]
			* [[Electrical double layer]]
			* [[Salting out]]

			==External links==
			* [http://www.bookrags.com/research/ionic-strength-woc/ Ionic strength]
			* [http://www.chembuddy.com/?left=pH-calculation&right=ionic-strength-activity-coefficients pH calculation — ionic strength and activity coefficients]

			== References ==
			{{refimprove\|date=October 2008}}
			*{{GoldBookRef\|title=ionic strength, ''I''\|file=I03180}}
			*{{Cite journal
			\| last1 = Debye
			\| first1 = P.
			\| last2 = Hückel
			\| first2 = E.
			\| year = 1923
			\| title = Zur Theorie der Elektrolyte. I. Gefrierpunktserniedrigung und verwandte Erscheinungen
			\| trans_title = The theory of electrolytes. I. Lowering of freezing point and related phenomena
			\| journal = Zeitschrift für Physik
			\| volume = 24
			\| pages = 305–324
			\| url = http://electrochem.cwru.edu/estir/hist/hist-12-Debye-1.pdf
			\| format = PDF
			}}
			*{{Cite book
			\| last = Skoog
			\| first = D.A.
			\| coauthors = West D.M., Holler F.J., Crouch S.R.
			\| year = 2004
			\| title = Fundamentals of analytical chemistry
			\| publisher = Brooks/Cole Pub Co
			\| isbn = 0-03-058459-0
			}}

			[[Category:Physical quantities]]
			[[Category:Analytical chemistry]]
			[[Category:Colloidal chemistry]]
			[[Category:Electrochemistry]]

en>SmackBot: remove Erik9bot category,outdated, tag and general fixes

2009-12-17T07:22:54Z

remove Erik9bot category,outdated, tag and general fixes

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Marvella is what you can contact her but it's not the most female name out there. Bookkeeping is her working day occupation now. South Dakota is where I've always been living. To collect coins is 1 of the things I adore most.<br><br>my homepage; [http://chatmast.com/index.php?do=/BookerSipessk/info/ over the counter std test]

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en>Addbot: Bot: Migrating 1 interwiki links, now provided by Wikidata on d:q2286211

en>SmackBot: remove Erik9bot category,outdated, tag and general fixes