Sodium paratungstate is a colorless triclinic crystal that has similar structure to ammonium paratungstate composition. Its chemical formula is Na10 (H2W12O42) •27H2O, molecular weight is 3596.50, and proportion is 3.987 (at 14°C).
Characteristics of Sodium Paratungstate
1. It dissolves in cold water.
2. It decomposes in hot water. It begins to lose water if it is heated to 100°C.
3. It is roughly equivalent to 12 aggregation state in solution. Metatungstate is available if continue to add acid to polymerization.
Preparation of Sodium Paratungstate
Hydrochloric acid (HCL) or nitric acid (HNO3) is dropwise added into the sodium tungstate solution under intense stirring and heating to pH value of 5~6.
Existence Form of Sodium Paratungstate in Ammonium Paratungstate Solution
The main existing form of sodium ion in ammonium paratungstate crystallization solution is sodium paratungstate.
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