Name: ___________________________
Reaction Kinetics Lab
Purpose:
The purpose of this lab is to determine the rate equation for the reaction between starch molecules (C6H12O6)n, sulphite ions (SO3-2), hydronium ions (H3O+) and iodate ions (IO3-).
Procedure:
1. Do each of the first five trials in the order shown by adding the reactants in the order shown (water first) to a 600 ml beaker with a magnetic stirrer. Note that the total volume in each trial is always 400 ml so that by doubling the volume of a particular reactant its concentration is doubled. By doubling the concentration of a reactant while keeping the other concentrations constant, you can determine the order of the reaction with respect to that reactant. Important Note: Make sure that the iodate solution is always the last reactant added to the reaction beaker. Begin timing as you add the iodate solution. (Add the iodate all at once as quickly as possible.)
2. After completing the first five trials predict what the reaction times should be for each of the remaining trials. Then perform those trials and compare your results with your predictions.
Data:
|
Trial |
Volume
(ml) |
Volume
(ml) |
Volume
(ml) |
Volume
(ml) |
Volume
(ml) |
Reaction |
Predicted |
|
Number |
of
Water |
of
Starch |
of Sulphite |
of
Acid |
of Iodate |
Time
(sec) |
Time
(sec) |
|
1 |
200 |
50 |
50 |
50 |
50 |
|
|
|
2 |
150 |
100 |
50 |
50 |
50 |
|
|
|
3 |
150 |
50 |
100 |
50 |
50 |
|
|
|
4 |
150 |
50 |
50 |
100 |
50 |
|
|
|
5 |
150 |
50 |
50 |
50 |
100 |
|
|
|
6 |
100 |
150 |
50 |
50 |
50 |
|
|
|
7 |
100 |
50 |
150 |
50 |
50 |
|
|
|
8 |
100 |
50 |
50 |
150 |
50 |
|
|
|
9 |
100 |
50 |
50 |
50 |
150 |
|
|
|
10 |
0 |
100 |
100 |
100 |
100 |
|
|
Conclusions:
1. The reaction is ____________ order with respect to starch.
2. The reaction is ____________ order with respect to the sulphite ion.
3. The reaction is ____________ order with respect to the iodate ion.
4. The reaction is ____________ order with respect to the hydronium ion.
5. The reaction is ____________ order overall.
6. Write the rate equation for the reaction: