Question

Results:

Slope 1	2	3	4
0.25516 kPa	0.09496 kPa	0.010285 kPa	.69419 kPa
20.9 C	20.9	20.9	34.2 C

The following mechanism has been proposed for this reaction:

H₂O₂ + I^- ---> IO^-+ H₂O (step 1, rate determining)

H₂O₂ + IO^----> I^- + H₂O + O₂ (step 2)

1. Identify any intermediate species and/or catalyst species in this mechanism.

2. What is the exact (not general) rate expression for the catalyzed reaction? Does your data from runs 1 – 3 support the rate expression? Explain.

3. Calculate the rate constant, k, at room temperature (average value) and room temperature + 10 °C. Hint: change your rate units into mol/L·s (using PV = nRT).

4. Determine the activation energy for the catalyzed reaction in kJ/mol using the two-point Arrhenius equation.

5. Do you expect the activation energy of the uncatalyzed reaction to be larger, smaller, or the same as the catalyzed reaction? Explain.