text: An example of back titration, the Volhard method, named after Jacob Volhard, involves the addition of excess silver nitrate to the analyte; the silver chloride is filtered, and the remaining silver nitrate is titrated against ammonium thiocyanate, with ferric ammonium sulfate as an indicator which forms blood-red [[Thiocyanate#Test for iron.28III.29|[Fe(OH)(SCN)]]] at the end point:
  : Ag (aq) + SCN (aq) → AgSCN (s) (K = 1.16 × 10)
  : Fe(OH)(OH) (aq) + SCN (aq)→ [Fe(OH)(SCN)]  + OH