. Sodium hypochlorite NaClO is the active ingredient in bleach. Cocentration of the hypochlorite ion determined in two ways
Stage 1 acidified iodide solution added to a solution of bleach and iodine formed
ClO- + 2I- + 2H+ = I2 + Cl- + H2O
Stage 2 iodine formed titrated with sodium thiosulfate solution
2S2O3 + I2 = 2I- + S4O6 2-
10cm3 of a household bleach diluted to 250cm3 in standard flask
25cm3 of this solution added to excess scidified potassium iodide solution
Solution the titrated against 0.10mol l-1 sodium thiosulfate
The volume of the thiosulfate required to reach end point was 20.5cm3
A) Calculate moles of iodine reacted in the titration
B) Calculate the concentration in mol l-1 of the ClO- in original household bleach
for part A I got 1.025x10 -3 moles
for part B I got 1.64x10-3 mol l-1
Could anyone tell me if this is the right answer because I can't find the answers to this question