View source for Benedict's reagent

'''Benedict's reagent''', also called '''Benedict's solution''', is a [[reagent]] used to test for [[reducing sugar]]s, named after American chemist [[Stanley Rossiter Benedict]]. Similar to [[Fehling's solution]], it is an alkaline solution of [[Copper|copper(II)]] stabilized by [[Citric acid|citrate]] ions.

==Reagent==
The reagent is prepared by dissolving 100&nbsp;g of anhydrous [[sodium carbonate]], 173&nbsp;g of [[trisodium citrate]] dihydrate and 17.3 g of [[copper(II) sulfate]] pentahydrate in water, and diluting to 1&nbsp;litre. The final solution is 71.3&nbsp;mmol/dm<sup>3</sup> in copper(II) and 588&nbsp;mmol/dm<sup>3</sup> in total citrate (eightfold excess). The copper(II) is believed to be present as a 1:1 citrate [[complex]], [Cu(C<sub>6</sub>H<sub>5</sub>O<sub>7</sub>)(OH)(H<sub>2</sub>O)<sub>''n''</sub>]<sup>2-</sup> (''n''&nbsp;= 0, 1).<ref>{{citation | first1 = Terrence B. | last1 = Field | first2 = Janet L. | last2 = McCourt | first3 = W. A. E. McBryde | title = Composition and Stability of Iron and Copper Citrate Complexes in Aqueous Solution | url = http://article.pubs.nrc-cnrc.gc.ca/ppv/RPViewDoc?issn=1480-3291&volume=52&issue=17&startPage=3119 | journal = Can. J. Chem. | year = 1974 | volume = 52 | pages = 3119–24}}.</ref>

==References==
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