Iodination of Acetone
Introduction and Goal
In this experiment we will be analyzing the rate of reaction with respect to
Acetone and Iodine with a Hydrogen Ion catalyst. When the color disappears (which
comes from the Iodine), the reaction will be complete. Using a larger concentration of
Acetone and Hydrogen Ion will ensure that Iodine is the limiting reagent (so the color
will disappear).
H+ (aq) + CH3COCH3 (aq) + I2  CH3COCH2I (aq) + H+ (aq) + I- (aq)
Materials Needed
4.0 M Acetone
Test Tubes
1.0 M HCl
10 mL Graduated cylinders
0.0050 M Iodine Solution (Lugol’s)
Stop Watches
Procedure
We will perform multiple trials for each run.
Run
1
2
3
4
4M
Acetone
2 mL
4 mL
2 mL
2 mL
1M
HCl
2 mL
2 mL
4 mL
2 mL
Water
4 mL
2 mL
2 mL
2 mL
0.005
M I2
2 mL
2 mL
2 mL
4 mL
1. Gather 3 test tubes and a beaker
2. Add the appropriate volume of reactants to each test tube. Add the acetone, then
water, then acid, and iodine last. As soon as the iodine is added, start the stop
watch.
3. When the solution turns clear, the reaction is over. Record the time.
4. Repeat steps 2 and 3 for runs 2 – 4, making sure to clean out the test tubes
thoroughly (and dry them) in-between each run.
The data table can be found on the back…
Data Table
Run
Elapsed Time
(seconds)
Average Time
∆𝑡(seconds)
∆[I₂] (M)
Rate (M/sec)
∆[𝐼 2 ]
∆𝑡
1
.001M
2
.001M
3
.001M
4
.002M
Rate Order Table
Assuming you placed the proper volume in each trial, this is the concentrations you
should have
Run #
[I2] (M)
[Acetone] (M)
[H+] (M)
1
2
3
4
0.001
0.001
0.001
0.002
0.8
1.6
0.8
0.8
0.2
0.2
0.4
0.2
Rate (from
above)
Analysis
Determine the rate order for acetone and hydrogen ion. Then, determine the k value for
the reaction. Finally, write the rate law for the reaction, including proper exponents.