Preparation of Barium Iodate Monohydrate

Amorphous barium iodate is formed when iodic acid solution is titrated with barium hydroxide or in the reverse titration. In such reactions, atmospheric carbon dioxide has to be excluded since it precipitates barium carbonate. An alternative preparation 

Weigh into a flask with a long neck 5 g sodium chlorate and 5 g powdered iodine. Add 40 cm water, shake to dissolve the chlorate and dien add 14 cm cone, nitric acid. Close the mouth of the flask with an inverted beaker. Heat gently with a small flame in the fume cupboard until the iodine has dissolved and then heat the open flask until the chlorine is boiled off, test with a moist blue litmus p r. Pour die contents into a 250 cm beaker. Use 30 cm water to wash die flask and to dilute the solution. Boil the beaker and maintain it on a boiling water bath. Dissolve 5.25 g barium nitrate in 50 cm water and add the solution slowly to the beaker, with continuous stirring. Cool to room temperature. Filter under suction and wash on the filter with small volumes of cold water. Dry by continued suction while pressing between filter paper. Record your yield and calculate the % yield based on Ba. 

Heat a little of the solid gently in a dry test tube and test any condensed liquid on the cool sides with a blue cobalt paper. Then heat more strongly inserting a glass wool plug near the mouth of the tube and expose to any gas, a glowing splint and a damp starch 

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