1) To determine the concentration of a sodium thiosulfate solution as in this experiment, a student pipetted 25.0mL of 0.100M potassium iodate (KIO3) solution into a 125mL Erlenmeyer flask. Potassium iodide and sulfuric acid were added as in this experiment. The titration needed 15.21mL of the sodium thiosulfate to reach the end point. What is the concentration of the sodium thiosulfate solution?
2) Into a 125mL Erlenmeyer flask was added some KI and H2SO4 as described in the procedure section of this experiment. Then 3.0mL of bleach solution was added to the flask and it was immediately titrated with 0.1261M sodium thiosulfate solution. It required 41.26mL of this sodium thiosulfate solution to reach the end point titration. What is the percentage of NaOH in the bleach? Assume the density of commercial bleaching to be 1.084 g/mL
3)What is the volume of sodium thiosulfate and water are needed to make an approximate 0.10M solution starting with 1.0M sodium thiosulfate solution.