Anhydrous sodium Sulfate (Na2SO4) is an inorganic salt that absorbs H2O in its crystalline lattice as crystallization water forming Na2SO4 * 10H2O. When added to an organic solvent containing traces of H2O the Na2SO4 "captures" the water and settles it on the bottom. Therefore it can be separated from the organic solution by filtration.
It is used in the glass industry as an agent of refining and Antischiumante.
Used in the textile industry as a pigments fixator and as a density corrector.
Used in the paper industry in the past as a whitening agent; The use is declining today due to the change in production processes.
Sodium sulfate tends to form insoluble incrustations that are difficult to remove, especially on silicone surfaces; These are easily attacked by sulphuric acid forming sodium hydrogenosulfate, which has a higher solubility in water.
- Na2SO4 + H2SO4 ⇌ 2 NaHSO4
Due to its low responsiveness, in the amateur chemistry laboratories, coarse bits of sodium sulfate of 2 to 4 millimetres, are used as boiling spheres as an alternative to the more common glass beads or pieces of porcelain.
Calculation PH Solution of sodium sulfate:
The ph calculation of an aqueous sodium sulfate solution is therefore quite similar to the ph calculation of any monoprotic weak acid. The PH value, as well as the concentration of the HSO4-ion, is determined by the value of its Ka, which corresponds to the Ka2 of sulphuric acid, equal to 1.2 × 10-2.
In the case of a 0.1 M solution of NaHSO4, for example, you have:
NaHSO4 → Na + + HSO4 –
HSO4 – + H2O ⇒ SO42-(sulphate ion) + H3O +
Ka = [SO42-]×[ H3O+]/[ HSO4–]