Stoichiometry: Sodium Hypochlorite & Potassium Iodide Reaction - Prof. Patricia G. Amateis, Lab Reports of Chemistry

Download Stoichiometry: Sodium Hypochlorite & Potassium Iodide Reaction - Prof. Patricia G. Amateis and more Lab Reports Chemistry in PDF only on Docsity! Ben Salsbury Partner: Justin Date Performed: 10/16/08 Date Submitted: 10/23/08 Daigiang Xu Stoichiometry Objective: To determine the stoichiometry of the reaction between sodium hypochlorite (NaClO) and potassium iodide (KI) in aqueous solution. Volume NaClO (mL) Volume KI (mL) Initial Temperature NaClO (°C) Initial Temperature KI (°C) Final Temperature (°C) 45.0 5.0 23.28 21.27 26.00 40.0 10.0 23.28 22.19 29.50 35.0 15.0 23.28 22.28 28.62 30.0 20.0 23.42 21.86 27.98 25.0 25.0 23.53 22.17 27.45 20.0 30.0 23.45 22.05 26.41 15.0 35.0 23.53 22.05 25.37 10.0 40.0 23.69 22.21 24.36 5.0 45.0 23.94 22.34 23.18 Sample Calculation: T initial= (23.28° C∗45mL )+(21.27° C∗5mL) (45mL+5mL) = 23.08°C Mole Fraction NaClO= Volume NaClO Volume NaClO+Volume KI = 50mL 45mL+5mL =1 ΔT=TT=Tfinal-Tinitial=26.00-23.08=2.92 Results and Conclusions: Volume NaClO (mL) Volume KI (mL) Initial Temperature NaClO (°C) Initial Temperature KI (°C) Final Temperature (°C) Initial Temperature (°C) 45.0 5.0 23.28 21.27 26.00 23.08 40.0 10.0 23.28 22.19 29.50 23.06 35.0 15.0 23.28 22.28 28.62 22.98 30.0 20.0 23.42 21.86 27.98 22.80 25.0 25.0 23.53 22.17 27.45 22.85 20.0 30.0 23.45 22.05 26.41 22.61 15.0 35.0 23.53 22.05 25.37 22.49 10.0 40.0 23.69 22.21 24.36 22.51 5.0 45.0 23.94 22.34 23.18 22.50 Initial (°C) ΔT (°C)T (°C) Mole Ratio 23.08 2.92 .9 23.06 6.44 .8 22.98 5.64 .7 22.80 5.18 .6 22.85 4.60 .5 22.61 3.80 .4 22.49 2.88 .3 22.51 1.85 .2 22.50 0.68 .1 Uncertainty: The most probable cause of uncertainty is caused by the delay in measuring the temperature of the solution after the reactants are mixed. A small amount of heat was likely lost to the environment in that time. Conclusion: Based on the graph (last page), the reaction is most efficient and is most complete at a mole ratio of about .82. This can be determined because the reactants reach their highest temperature at that ratio. Definitions: Stoichiometric coefficient- the whole numbers relating the number of moles of one substance to another in a chemical reaction. Mole fraction- the whole number ratio of the number of moles of a given component of a mixture to the total number of moles of all the components. Molarity- the number of moles of solute per liter of solution.