en>Michael Hardy: /* Explanation */

2014-01-19T23:37:24Z

Explanation

← Older revision		Revision as of 01:37, 20 January 2014
Line 1:		Line 1:
	~~Alyson~~ is the ~~title people use~~ to ~~best psychic readings (~~[~~http://chorokdeul~~.co.kr/~~index.php?document_srl=324263&mid=customer21 please click the following website~~]) contact me and ~~I think it sounds fairly great when you say it~~. ~~What me~~ and ~~my family members love is bungee leaping but I've been using on new things recently~~. ~~For many years she's been residing in Kentucky but her husband desires them~~ to ~~move~~. ~~Office supervising~~ is ~~what she does for a residing.~~<br><br>~~Also visit my page; email~~ [~~http~~:/~~/kjhkkb.net/xe/notice/374835 psychic love readings] readings~~ ([~~http://www~~.~~edmposts~~.~~com~~/~~build-~~a-~~beautiful-organic~~-~~garden~~-~~using~~-~~these~~-~~ideas/ learn this here now])~~		{{Refimprove\|date=February 2013}}

			The '''quinhydrone electrode''' is a type of [[redox]] [[electrode]] which can be used to measure the hydrogen ion concentration ([[pH]]) of a solution in a chemical experiment. It provides an alternative to the commonly used [[glass electrode]] in a [[pH meter]].<ref>Vonau, W. Guth, U. 2006. pH monitoring: a review</ref>

			The electrode consists of an inert metal electrode (usually a [[platinum]] wire) in contact with [[quinhydrone]] crystals and a water-based solution. Quinhydrone is slightly soluble in water, dissolving to form a mixture of two substances, quinone and hydroquinone, with the two substances present at equal concentration. Each one of the two substances can easily be oxidised or reduced to the other.

			The potential at the inert electrode depends on the ratio of the [[activity (chemistry)\|activity]] of two substances ([[quinone]]-[[hydroquinone]]), and also the hydrogen ion concentration. The electrode half-reaction is:

			Hydroquinone ↔ Quinone + 2H<sup>+</sup> +2e<sup>-</sup>

			Because the electrode [[half-reaction]] involves hydrogen ions, the [[electrode potential]] depends on the activity of hydrogen ions. From the [[Nernst equation]]:
			:<math>E= E^0 + \frac{RT}{nF} \ln a_{H^{+}}</math>

			For practical pH measurement, a second pH independent reference electrode (such as a [[silver chloride]] electrode) is also used. This reference electrode does not respond to the pH. The difference between the potential of the two electrodes depends (primarily) on the activity of H<sup>+</sup> in the solution. It is this potential difference which is measured and converted to a [[pH]] value.

			The quinhydrone electrode is not reliable above pH 8. It is also unreliable in the presence of strong oxidising or reducing agents, which would disturb the equilibrium between hydroquinone and quinone. It is also subject to errors in solutions containing proteins or high concentrations of salts.{{Citation needed\|date=May 2009}}

			Other electrodes commonly used for measuring pH are the [[glass electrode]], the [[hydrogen electrode]], the antimony – antimony oxide electrode, and the ion-sensitive field effect transistor [[ISFET]] electrode.

			== References ==
			{{reflist}}

			[[Category:Electroanalytical chemistry devices]]
			[[Category:Electrodes]]


			{{analytical-chem-stub}}
			{{physical-chemistry-stub}}

en>Lgstarn: /* Explanation */

2012-06-13T17:43:17Z

Explanation

New page

Alyson is the title people use to best psychic readings ([http://chorokdeul.co.kr/index.php?document_srl=324263&mid=customer21 please click the following website]) contact me and I think it sounds fairly great when you say it. What me and my family members love is bungee leaping but I've been using on new things recently. For many years she's been residing in Kentucky but her husband desires them to move. Office supervising is what she does for a residing.<br><br>Also visit my page; email [http://kjhkkb.net/xe/notice/374835 psychic love readings] readings ([http://www.edmposts.com/build-a-beautiful-organic-garden-using-these-ideas/ learn this here now])

Fraction of variance unexplained - Revision history

en>Michael Hardy: /* Explanation */

en>Lgstarn: /* Explanation */