Given that 31.6ml of 0.141M Na2S2O3 is needed to reach the stoichiometric point how many grams of Cl2 are in the titrated?

Answer 1

Thiosulfate: 2 S2O32- --> S4O62- + 2e-

equivalency to:

Chlorine: 1 Cl2 + 2e- --> 2Cl-

31.6 ml * 0.141 mmol/ml S2O32- = 4.456 mmol S2O32-

= 4.456 *(2 electron / 2 S2O32-) = 4.456 mmol (electrons) =

= 4.456 *(1 Cl2 / 2 electron) = 2.228 mmol Cl2 =

= 2.228 * 70.90 mg/mmol Cl2 = 158 mg =

= 0.158 g Chlorine