Include a trendline and its equation and R
value on your graph.
This is done by rightclicking on one of the data points on
your graph and choosing "Add Trendline" from the drop down menu.
The first tab asks what type of trendline you wish to
use, and the Options tab allows you to include the trendline equation and R
value.
Order with respect to BrO
:
first order
(round to the nearest whole number)
Reaction Order Determination for H
+
Place your plot relating to the reaction order for H
here (cover this instruction box so that
your graph is an appropriate size).
Properly label your graph (labels for axes, including units, and a title).
Include a trendline and its equation and R
value on your graph.
This is done by rightclicking on one of the data points on
your graph and choosing "Add Trendline" from the drop down menu.
The first tab asks what type of trendline you wish to
use, and the Options tab allows you to include the trendline equation and R
value.
Order with respect to H
:
second order
(round to the nearest whole number)
Calculation of Rate Constant, k
Determination of Activation Energy, E
a
Type your calculation of "k" here:
k=rate/[BrO3]^b[I]^i[H3O+]^h= (3.0e8)/(0.0080M)^1(0.0020M)^1(0.0200M)^2= 4.6875
Type your calculation of E
here:
ln(k1/k2) = Ea/R(1/T2  1/T1) > Ea = Rln(k1/k2)/(1/T2  1/T1)
Ea= (8.314 J/K.mol)(ln(8.53125/17.76)/(1/298.2667  1/273) = 19645.314 J/mol = 19.645 kJ/mol
Type an example calculation for determining the CV+ concentration from the absorbance data:
A=[CV+]e where e=absorptivity and A=absorbance so,
[CV+]=absorbance/absorptivity
=(0.172/41761.71352)= 1.7241e6 M
Results and Discussion
Part I
1. Based on your data, write out the complete rate law including value and units for the rate constant. (1
pt)
Rate=k[BrO3]^b[I]^i[H3O]^h > Rate= (17.76 L^2/(mol^2*s))*[BrO3][I][H+]^2
2. The literature values for the reaction orders are 1 for BrO
and I
and 2 for H
Compare the accuracy
of your orders to these literature values. (Calculate the % error.)
Discuss your most likely sources of
error. (2 pts)
BrO3 = (1.00.705)/(1.0) = 29.5%
I = (1.00.6862) = 31.38%
H+ = (2.07532.0) = 3.765%
Overall my literature values were pretty accurate, especially for H+.
One sorce of error may have been that the reaction of the timer was slow, which would have made the time
innacurate.
Anohter sorce of error would have been that the date was transfered inaccurately by other students
in other groups.
3. How do the activation energies for the catalyzed and uncatalyzed reaction compare (include a %
difference in your discussion)? Is this in line with what is expected? (2 pts)
The Ea for the uncatalyzed reaction was 19.645 kJ/mol and 43.59 kJ/mol for the catalyzed rection.
43.59
19.645/43.59 = 54.932%.
This is not as I wouldhave expected it to be because during the reaction, the catalyst
allowed the reaction to proceed more quickly.
The error in this calculation must have stemmed from the times
recorded for these trial runs.
Part II
1. Based on your data, write out the complete rate law including value and units for the rate constant.
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 Spring '08
 N.
 Reaction, Kinetics, Run, Rate equation, CV+

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