Ferric ammonium sulfate is an inorganic compound with a chemical formula of NH4Fe(SO4)2, a violet crystal. Used as an analytical reagent, as an indicator in the determination of halogen. Store in a cool, ventilated warehouse. The storage temperature should not exceed 37°C. It should be stored separately from oxidants and edible chemicals, and avoid mixed storage. Keep the container tightly closed.
Used as an analytical reagent, as an indicator in the determination of halogen.
Ferric ammonium sulfate indicator method should be carried out in dilute nitric acid solution, because iron ions can form iron hydroxide precipitates in neutral or alkaline media. In order to prevent precipitation conversion (AgCl+SCN-→←AgSCN+Cl-), after precipitation by adding silver nitrate titrant with ferric ammonium sulfate indicator method, 5ml dibutyl phthalate or 1～3ml nitrobenzene should be added, and After shaking vigorously, add the indicator solution and titrate with the ammonium thiocyanate titrant. The titration should be carried out at room temperature. The red complex is easy to fade when the temperature is high. Shake vigorously during titration to avoid precipitation and adsorption of silver ions and reach the end prematurely. But when the titration is close to the end point, shake it gently to reduce the contact between silver chloride and SCN- to avoid precipitation and transformation.
