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T-6
EXPERIMENTAL PROCEDURE
I. Activation Energy
Record the concentration of the Na2S2O3 from the stock bottle in the space provided on your
Observations Sheet.
The procedure used in the previous experiment will be followed except that the temperature will be
varied. The approximate temperatures to be used are 10°C above room temperature, 20°C above
room temperature, room temperature, 10
C below room temperature and 20°C below room
temperature. Carry out individual runs as outlined below and refer to the previous experiment for
experimental details. Record your data on the Observations Sheet.
Each run will require a 125 mL Erlenmeyer flask and 100 mL beaker. In order to perform the
experiment efficiently, wash three sets of this glassware (i.e. 3 flasks and 3 beakers). The Erlenmeyer
flasks and 100 mL beakers must be cleaned thoroughly before use. Make sure that there are no
traces of soap remaining in the beaker or flask. Before each run, rinse the glassware four times
with tap water and twice with DI water
then DRY the glassware so the reagent solutions are not
diluted.
Label the flask and beaker in each set with #1 for the first set, #2 for the second set and #3 for the
third. Use one set to prepare the solutions for the room temperature runs, one set for the reaction runs
done at temperatures lower than room temperature and one set for the runs warmer than room
temperature.
Prepare 3 sets of reaction solutions being careful to keep the flask and beaker of each set together.
Carefully measure into each 125 mL Erlenmeyer flask:
10.00 mL KI from the buret, 5.00 mL Na2S2O3, 3 drops starch and
2 drops of EDTA solution
