Prepare 0.1 mol/l Ceric Ammonium Sulfate

General Information:

    One liter of this solution contains 66.858 g of ceric ammonium sulfate (Ce(SO4)2ŋ2(NH4)2SO4ŋ4H2O, molecular weight: 668.58). 

Procedure:
    Weigh 67 g of ceric ammonium sulfate, and dissolve in 0.5 mol/l sulfuric acid
to make 1,000 ml. Standardize before use.

Standardization:   

     Measure exactly 25 ml of 0.1 mol/l ceric ammonium sulfate, add 20 ml of water and 20 ml   

     of diluted sulfuric acid (1 ˠ 20), dissolve 1 g of potassium iodide, and titrate immediately   

     with 0.1 mol/l sodium thiosulfate. When the color of the solution changes to light yellow  

     near the end point, add 3 ml of starch TS as the indicator, and continue the titration until  

     the blue color of the solution disappears. Perform the  blank test, and make any necessary  

     correction.