Iodometric Titration Lab

The purpose of this lab is to gain experience because an Iodometric titration was preformed and to determine the molarity and mass percent of an analysts in an commercial product. In this experiment my partner and I prepared 500mL of 0.07M sodium thiosulfate pentahydrate. As well, we added 0.05 grams of sodium bicarbonate and mixed it together with DI water. We got 60 mL of sodium thiosulfate solution in a clean 100-mL beaker. Then filled the buret to just above the 0 mL mark with sodium thiosulfate solution. Allowed a few milliliters to pour through the buret tip so that any trapped air can be flushed through. Then we recorded the initial buret level to the nearest 0.05 mL. As we used a clean 25-mL volumetric pipet to deliver 25.00 mL of bleach solution into a clean 250-mL volumetric flask we also added distilled water to the mark of the volumetric flask.
The titration takes place in a 250-mL Erlenmeyer flask which we labeled as trial 1-3. Some other materials we used was the 25-mL volumetric pipet, preciously add 25.00 mL of diluted bleach (from step 2) to the reaction flask. Using a 100-mL graduated cylinder, add about 15 mL of distilled or deionized water to the reaction flask. Used a 100-mL graduated cylinder, add about 20 mL of 10% potassium iodide solution to the reaction flask. This 10% KI solution should be clear, and not yellow. Pour about 2 mL of starch solution in a 10-mL graduated cylinder and place the cylinder next to the reaction flask. This starch solution will be added to the flask later.