The table below summarizes the preparation of the test solutions. Measure the volumes ofte +0.05 mL using either a pipet or a buret. All .
Solution B
starch 0.02M Na S203 0.1M K 5,0
Test
Soln Water
1
148
2
138
3 128
4 108
88
0.3M KI
10
2
10
20
2
10
30
2
10
30
2
10
2
10
30
30
30
50
70
30
1. Prepare solution A in a 250 mL beaker or 250 mL Erlenmeyer flask. Stir the solution
2. The reaction begins when solution B is poured into solution A, therefore, be prepared to start
timing the reaction in seconds with a watch or clock. Place the reaction vessel on a white sheet
of paper so that the color change is more
Calculations
trials.
1. Determine the initial concentration, after mixing, of both persulfate and iodide ions for all
2. Determine the rate for each trial in mmols iodine/sec.
3. Using trials 1, 2, and 3 plot log rate vs. log([I']). Determine q from this plot.
5. Using the p and a determined in steps 3 and 4 and the measured rate, substitute into the rate
equation for each trial and determine k. Calculate the average k.