BlueCream

Determination Of SO 4 in Na 2 SO 4 .10H 2 O THEORY                 Sulfuric can be precipitated out of salt solution as Barium Sulfate (BaSO 4 ) in acid condition to avoid precipitation of another Ba, such as BaCO 3 and Ba 3 (PO 4 ) 2 . To avoid coprecipitation of BaCl 2 should dilute little by little. Aging conducted in hot conditions to enlarge the crystal and to reduce coprecipitation. The sediment of BaSO 4 was so subtle so make it’s easy to creep upward.   In ignition sediment of BaSO 4 can be reduced by carbon from filter paper to be BaS. BaSO 4    +    4C                         ㅡ >       BaS    +    4CO BaSO 4    +    4 H 2 O                   ㅡ >      BaS    + 4 H 2 O                         Therefore, after the carbon is lost, the rest of incandescent added 1 drop   of concentrated H2SO4 and burning it again to change BaS become BaSO4. BaS    +    H 2 SO 4           ㅡ >       BaSO 4      +    H 2 S Basic In condition acid and heat sulfuri