353 Table 1: Grid indicating the solutions to add for each initial rate experiment: | Initial rate experiment1 Initial rate experiment 2 Initial rate experiment 3 10.0 mt Kfterg)_v 10.0 mL KI(aq 5.0 mL KI(aq) v Add first 5.0 mL Na2S2O3(aq) 5.0 mL Na2S;Ostag 5.0 mL Na2S2O3(aq) 10 mL starch(aq) 5.0 mL NaCl(aq) v 1.0 mL starch(aq) 1.0 mL starch(aq) v Add last, 10.0 mL K2S2O3(aq) start timer 5.0 mL K2S2O3(aq) 10.0 mL KS203(aq) Part A: Determination of rate law Y Collect the following solutions in separate small, clean, and dry beakers (label them!): 15-20 mL of 0.10 M Na2SO4 130 mL of 0.10 M KI 15-20 mL of 0.10 M NaCI 130 mL of 0.10 MK28208 15-20 mL of starch solution SV Obtain three large (25 x 200 mm) test tubes, and make sure that they are clean and as dry as possible. You will also need a digital thermometer and a timer. . You will perform three initial rates experiments. Table 1 provides the final contents for each of three initial rates experiments. You will set up and run three trials for each initial rates experiment in the three test tubes. For each initial rates experiment: . Add the amount of KI solution indicated in Table 1 using a digital pipette to the three test tubes. Rinse the pipette tip with distilled water. b. Where required, add the indicated amounts of NaCl and Na2SO4 solutions using the digital pipette to the three test tubes. Rinse the pipette tip with distilled water between solutions. c. Add 1.0 mL of starch solution using the digital pipette to each one of the three test tubes. Rinse the pipette tip with distilled water. d. Add 5.0 mL Na2S2O3 solution using the pump dispenser to each one of the three test tubes. e. Do the following one test tube at a time for all three test tubes: Start the timer as you deliver the indicated amount of K2520s solution using the digital pipette. Stir the solution at a constant rate using a digital thermometer - consistency in your rate of stirring for all initial rates experiments is important! Stop the timer at the first sign that the solution has turned blue-black, and record time and the temperature at this point. - OT Ask your TA to check your data for Part A before starting Part 3 + = 1956°C Xı NaaS303, Stoch. Clar 19.4°C SOSec
The reaction was run three times with different initial concentrations of the reactants yielding the following rates:
b)Determine the reaction order with respect to HBPB2-
c)Determine the reaction order with respect to OH-
d)Calculate the rate constant for this reaction at 20 oC
e)What is the ârate lawâ for this reaction?
f)What other information do you need to calculate the activation energy for this reaction?
2. Why is it better to transfer one group of solutions into one flask and a second group into a second flask and then mix them, instead of pipetting the solutions sequentially into the same flask?
3. What will be the concentration of [I-] in the reaction flask after mixing (See Run #6): 1.0 ml starch + 2.0 mL 1.2 x10-2 M Na2S2O3 + 4.0 mL 0.20 M KI + 4.0 mL 0.20 M KNO3 + 4.0 mL 0.20 M (NH4)2S2O8 + 4.0 mL 0.20 M (NH4)2SO4 ?
4. What will be the concentration of [S2O82-] in the same reaction mixture as above?