抄録
Transition metal compounds, iron(III) chloride hexahydrate (FeCl_3・6H_2O) and cobalt(II) chloride hexahydrate (CoCl_2・6H_2O) are examined as inorganic indicators in acid-base solution and in acid-base titration method. These two inorganic indicators were applied for house hold materials to identify whether they are acid or base.