# Investigating The Mass Rate Of Sodium Hypochlorite

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INTRODUCTION: The purpose of this two-part experiment was to “determine the mass percent of sodium hypochlorite in a commercial chlorine bleach sample” (lab website). Titration is used in this lab twice. In Part one, students will use the solution of KIO3 primary standard and use this solution to standardize a solution containing sodium thiosulfate. When the KI is added to the solution, it forms a brown/yellow color. Then students used titration to add Na2SO3 to make the color go from brown/yellow to colorless. In the second part of the lab, students used the standardized Na2SO3 solution to determine the mass percent of sodium hypochlorite in the commercial chlorine bleach. Students used titration to the standard solution of Na2SO3 to…show more content…
After this, students used titration to add Na2SO3 to make the color go from brown/yellow to colorless and then used that to figure out the concentration of Na2SO3. Having balanced chemical equations are important because students need to use the mole to mole conversion and if the equation isn’t balanced correctly, the numbers that the students use in the experiment will be messed up. The products on one side have to equal the reactants on the other side in order to be useful. The molarity of KIO3 that students started off with was 0.01 M. Group two expected to get similar results to that molarity. Instead, the actual results in the first trial concluded to be 0.098 M and 0.108 M for the second trial. The composition of the commercial bleach ended up to be 8.77%. Sources of error could’ve come from the calculations. Students could’ve miscalculated and that messed up there results. Also, since measurements had to be exact, students could’ve put more or less of the solution in than that was needed. Another source of error could’ve come from the titration part. Since group