how does sodium thiosulfate neutralize chlorine
S2O3^= is oxidized to S4O6^= and perhaps higher. Cl2 is reduced to Cl^-
Sodium thiosulfate can neutralize chlorine through a chemical reaction. When dissolved in water, sodium thiosulfate reacts with chlorine to form sodium chloride, sodium sulfate, and sulfur (or sulfur dioxide) as byproducts. The reaction can be represented as follows:
2Na2S2O3 + Cl2 -> 2NaCl + Na2SO4 + S (or SO2)
To actually neutralize chlorine using sodium thiosulfate, you would need to follow these steps:
1. Determine the concentration of the chlorine solution you want to neutralize. This is usually measured in ppm (parts per million) or mg/L.
2. Calculate the amount of sodium thiosulfate needed to neutralize the chlorine. The stoichiometry of the reaction indicates that for every mole of chlorine (Cl2), two moles of sodium thiosulfate (Na2S2O3) are required.
3. Convert the concentration of chlorine from ppm or mg/L to moles by dividing by the molar mass of chlorine (Cl2 = 70.9 g/mol).
4. Use the stoichiometric ratio from step 2 to determine the moles of sodium thiosulfate needed.
5. Convert the moles of sodium thiosulfate to the required weight by multiplying by its molar mass (Na2S2O3 = 248.2 g/mol).
6. Weigh out the calculated amount of sodium thiosulfate and dissolve it in water.
7. Add the sodium thiosulfate solution to the chlorine solution gradually while stirring. The reaction will occur, leading to the formation of sodium chloride and other byproducts, effectively neutralizing the chlorine.
It's important to note that this process requires accurate measurement of the concentrations and precise calculation of the amounts needed for effective neutralization. It is recommended to consult a professional or refer to specific guidelines for accurate determination of the required sodium thiosulfate dosage.