CHEM 21131 Physical Chemistry Laboratory
2014
Pre Lab – Experiment C7
Iodination of acetone
1. In a reaction involving the iodination of acetone, the following volumes were used to
make up the reaction mixture,
10 mL, 4.0 M acetone + 10 mL, 1.0 M HCl + 10 mL, 0.0050 M I2, + 20 mL, H20
Using the reaction mixture, a student found that it took 250 seconds for the colour of the
I2 to disappear.
What was the rate of the reaction?
[Hint: First find the concentration of I2 in the reaction mixture, [I2]. Then use Equation:
rate=Δ[I2]/Δt].
2. A chemist studying the iodination of acetone performed two trials with the following
mixtures:
volume (mL) of
4 M Acetone
volume (mL)
of 1 M HCl
volume
(mL) of
0.005 M I2
volume (mL)
of water
Time (sec)
I
10.0
10.0
10.0
20.0
250
II
20.0
10.0
10.0
10.0
120
Trial
(a) Find the concentration of each reactant in Mixture I.
[acetone] =
[I2] =
[H+] =
(b) Calculate the rate of the reaction in each Trial.
Rate I =
Rate II =
(c) Write the Rate Law for each Trial, plugging in values for all concentrations
and for the rate.
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CHEM 21131 Physical Chemistry Laboratory
2014
Rate II =
Rate I =
Divide Rate II by Rate I to determine the order with respect to acetone.
3. Define the following terms,
(a) differential rate law (b) integrated rate law.
4. Summary of the kinetics for reactions of the type A→ products that are zero, first or
second order in [A] is given below. Complete the table.
Order
Rate Law
0
rate = k
Integrated Rate Equation
Linear Plot
Slope
Units for k
[A] vs time
-k
M/s
1
2
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