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.)

 

  1. 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: