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| '''Precipitation''' is the condensation of a [[solid]] from a [[solution]] during a [[chemical reaction]]. This occurs when the solution is [[supersaturated]], whereupon the solid forms from the solute phase, and usually sinks to the bottom of the solution.
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| This effect is useful in many industrial and scientific applications whereby a chemical reaction may produce a solid that can be collected from the solution by various methods (e.g. filtration, decanting, centrifuging).
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| ==Detection of cations==
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| Precipitate formation is useful in detecting the type of [[cation]] in an unknown [[salt]]. To do this, an [[alkali]] first reacts with the unknown salt to produce a precipitate which is the hydroxide of the unknown salt.
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| To identify the cation, the colour of the precipitate and its solubility in excess are noted.
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| ==External links==
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| * http://www.chs.edu.sg/~limth/lessons/2002/qa/cations.htm
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