Thursday, February 26, 2009

Chloride by Mohr's Method

Mohr's method determines the chloride ion concentration of a solution by titration with silver nitrate. As the silver nitrate solution is slowly added, a precipitate of silver chloride forms.
Ag+(aq) + Cl-(aq) --> AgCl(s)
The indicator used is dilute potassium chromate solution. When all the chloride ions have reacted, any excess silver nitrate added will react with chromate ions to form a red-brown precipitate of silver chromate. This procedure is known as Mohr’s method.
2Ag+(aq) + CrO42-(aq) --> Ag2CrO4(s)
The procedure described here for seawater may also be applied to water samples from various other sources to determine the relative concentrations of chloride ions in, e.g., stream water, river water, estuary water.

1 comment:

  1. hi

    in volhard method the sample solution should be in acidic condition

    what PH range and how can be made? (by nitric acid or some )else

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