Suppose a student diluted and titrated a bleach unknown. A single titration was performed which required 14.42 mL of 0.100 M Na2S2O3.
The density of the original, undiluted bleach unknown was 1.042 g/mL.
calculate the number of moles of ClO- in the sample titrated.
You're post is too sketchy. For example, did you add KI to the bleach to free up I2 and the I2 was titrated with thiosulfate? Of did you use some other procedure.
sorry this is for a prelab. But yes.
ClO^- + 2I^- ==> I2 + Cl^- then the titration step is
I2 + 2S2O3^2- ==> S4O6^2- + 2I^-
1 mol ClO^- = 1 mol I2
1 mol I2 = 2 mol S2O3^2-
therefore, 1 mol ClO^- = 2 mol S2O3^2- or
1/2 mol ClO^- = 1 mol S2O3^2-
mols S2O3 = M x L
mols ClO^- = 1/2 that.
thank you
one last question.
From same set up.
Assuming all of the hypochlorite ion comes from sodium hypochlorite, calculate the grams of NaClO in the titrated bleach sample.
mols ClO^- x molar mass NaClO = ?
5 mL of undiluted bleach was used. Calculate the mass in grams of undiluted bleach that was in the sample of bleach titrated.
The same answer as previous.
mols ClO^- x molar mass NaClO = grams NaClO.
If you want percent then
(g bleach/g sample)*100 = ?
g bleach from above.
g sample = 5 mL x density g/mL = grams sample