The method describes how to determine the chloride content in water by means of the analytical method according to MOHR.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Chloride ions are found in natural waters in a wide range of concentrations. A high chloride content can be the result of substantial contamination. In brewing liquor, chloride can have an impact on the character of the beer. At higher concentrations (approx. > 100 mg/l), it can induce corrosion in brewing equipment, even of stainless steel (in hot water, approx. > 50 mg/l).
Transformation of the chloride ions in the presence of silver ions produces silver chloride, which is not very soluble, until all the chloride ions are bound. The excess silver ions react with chromate ions to silver chromate, which exhibits a reddish brown color:
Cl - + Ag+ → AgCI
2 Ag+ + CrO42- → Ag2CrO4