- Source: Sodium tetrathionate
Sodium tetrathionate is a salt of sodium and tetrathionate with the formula Na2S4O6.xH2O. The salt normally is obtained as the dihydrate (x = 2). It is a colorless, water-soluble solid. It is a member of the polythionates, which have the general formula [Sn(SO3)2]2-. Other members include trithionite (n = 1), pentathionate (n = 3), hexathionate (n = 4).
Sodium tetrathionate is formed by the oxidation of sodium thiosulfate (Na2S2O3), e.g. by the action of iodine:
2 Na2S2O3 + I2 → Na2S4O6 + 2 NaI
The reaction is signaled by the decoloration of iodine. This reaction is the basis of iodometric titrations.
Other methods include the coupling of sodium bisulfite with disulfur dichloride:
2 NaHSO3 + S2Cl2 → Na2S4O6 + 2 HCl
The ion has ideal C2 symmetry, like H2S2. The S-S-S dihedral angle is nearly 90°. The central S-S distance is 2.115 Å, 0.01 Å longer than the two other S-S distances as well as those distances in most polysulfanes.
References
Kata Kunci Pencarian:
- Sodium tetrathionate
- Tetrathionate
- Sodium thiosulfate
- Thiosulfate
- Trithionate
- Mathurin-Joseph Fordos
- Polythionates
- Polythionic acid
- Potassium thiosulfate
- Sulfur
