Experiment 2 Lab Report
1. Ken McFarland “Kinetics of Hydrogen Peroxide Oxidation of Iodine” , CHEM 1130, TA Nastaran Marzijarani, Section 108, Room 1871, Will Brubacher,
2. Purpose of Experiment: This experiment is to determine the rate law of the reaction of
hydrogen peroxide and potassium iodide.
3. Procedures: This experiment will require 5 250mL beakers, 5 small beakers, a stopwatch, a
thermometer, buffer solution, starch solution, 0.300 M potassium iodide, 0.200M sodium
thiosulfate, and 0.100 M hydrogen peroxide, and several sheets of white paper. The first step
is to prepare your first solution.
Solution
Volumes (mL)
Number
Buffer
0.300 M Starch 0.0200 M
Water
0.100 M
Total
KI
Na2S2O3
H2O2
Volume
1
5.00
1.50
1.00
5.00
82.5
5.00
100.0
2
5.00
3.00
1.00
5.00
81.00
5.00
100.0
3
5.00
5.00
1.00
5.00
79.00
5.00
100.0
4
5.00
5.00
1.00
5.00
74.00
10.00
100.0
5
5.00
5.00
1.00
5.00
64.00
20.00
100.0
Everything except the hydrogen peroxide is to be added, in the order listed, into the first 250
mL beaker. In one of the small beakers, place 5 mL of H202. This is added to the solution in
the 250 mL beaker, and a portion of the resulting solution is quickly poured back and forth
between the two beakers, to insure that all of the H2O2 is in the larger beaker. The stopwatch
should be started as soon as the two solutions are mixed. Place the beaker on one of the
sheets of paper, so that the color change can be easily observed. While you are waiting for
the color change to occur, which will take in excess of 15 minutes, continue to prepare
solutions two through five, using the same procedure as solution one, varying the amounts as
listed in the table. Record the time to completion of all five of the reactions to the nearest
second.
4. Observations, Calculations, Results and Data Sheets: All data is on attached spreadsheet.
Data from all calculations are also included.
5. Questions
1. Rate=k[H2O2][I-]
2. a) first order
b) first order
3. 0.008528951 M-1s-1