Fill the buret 4/5 full with the standardized sodium thiosulfate solution and record the concentration of this solution on your Observations Sheet. Read the initial level of the buret containing...

Fill the buret 4/5 full with the standardized sodium thiosulfate solution and record the concentration of this solution on your Observations Sheet. Read the initial level of the buret containing sodium thiosulfate (to 0.01 mL), and record this on your Observations Sheet. Begin the titration of the aqueous layer aliquot by slowly adding the thiosulfate titrant to the Erlenmeyer flask. Continue adding thiosulfate, while swirling the flask, until the solution tums a pale yellow (exact point is not too important here). Add 3 drops of starch solution and then continue the titration until the solution tums from blue to colorless on one drop of titrant.