Question

single titration was performed which required 11.82 ml of .1 M Na2S2O3

the density of the original undiluted

bleach unknown was 1.04 g/ml

calculate the number of moles of ClO- in the sample titrated
ClO- + 2I- + 2H+ === I2 + Cl- + H20

I2 + 2S2O2/3- === 2I- + S2O2/6-

Answer 1

Your second equation is not right. It should be
I2 + 2[S2O3]^2- ==> [S4O6]^2- + 2I^-
1 mol ClO^- = 1 mol I2 = 2 mols [S2O3]^2-; therefore, 1 mol ClO^- = 2 mols [S2O3]^2-.

mols S2O3]^2- = M x L = ?
mols ClO^- = 1/2 mols [S2O3]^2-