1. mols = M Na2S2O3 x L Na2S2O3
2. What are you calling reaction 1 and reaction 2?
3,4,5. What is the volume of the bleach. How much was it diluted?
Suppose a student diluted and titrated a bleach unknown exactly as described in the experimental procedure, except only a single titration was performed which required 13.73 mL of 0.100 M Na2S2O3.
The density of the original, undiluted bleach unknown was 1.04 g/mL
1. Calculate the number of moles of Na2S2O3 used in the titration
2. Calculate the number of moles of ClO- in the sample titrated. Hint: The moles of thiosulfate simply equals the moles of sodium thiosulfate. From the moles of thiosulfate the moles of I2 can be easily determined from reaction (2). Now use reaction (1) to get the moles of hypochlorite, ClO−.
3. Calculate the grams of NaClO in the titrated bleach sample, assuming all of the hypochlorite ion comes from sodium hypochlorite. Hint: The moles of sodium hypochlorite is simply the same as the moles of hypochlorite.
4. Calculate the mass in grams of UNDILUTED bleach that was in the sample of bleach titrated.
5. Using the UNROUNDED answers to questions 3 and 4, calculate the weight percent of NaClO in the undiluted bleach sample. Hint: Weight percent is the same thing as percent by mass.
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