Chemical reaction (insert the chemical reaction of 2-chloro-2-methylpropane being studied in this project)
1) Fill in your kinetic data in the table below, paying attention to indicated units.
Reaction Temperature (K) Reaction Time (s) k Value (s-1) Average k ± standard deviation
Low Temp Rep 1
Low Temp Rep 2
Low Temp Rep 3
Room Temp Rep 1
Room Temp Rep 2
Room Temp Rep 3
High Temp Rep 1
High Temp Rep 2
High Temp Rep 3
2:1 Acetone/Water —
2-bromo-2-methylpropane —
2) Show how you calculated one of the k values in the Table above.
3) Insert your Arrhenius plot graph as an image file below. Your graph should have three data points (representing the average k value at each temperature) with error bars (representing ) and a line of best fit labeled with the slope, intercept, and R2 value. In addition, it should be scaled properly, have a meaningful title and correctly labeled axes.
4) Based on your line of best fit, what is the energy of activation and pre-exponential factor (pay attention to units). Then, show the calculation of each component.
Ea = ______________________________
A = _______________________________
5) What is the entropy of activation (ΔS‡) according to your graph. Is this value what you would have expected from an SN1 reaction? Why or why not? Explain on a molecular level what your ΔS‡ value means for the hydrolysis of 2-chloro-2-methylpropane.
ΔS‡ = _____________________________
6) Look up the literature value of the C–Cl bond dissociation energy (BDE) of 2-chloro-2-methylpropane and compare this value with the experimentally determined Ea for this reaction. If the values differ then provide a reasonable explanation for this. (HINT: How is the BDE determined?)
BDE = ___________________________
7) Compare the rate constant k you calculated for the 2:1 acetone/water solvent system to the k you calculated for the 1:1 acetone/water solvent system. Explain any difference in rate constants based on a molecular understanding of an SN1 reaction.
8) If this experiment was done, compare the rate constant k you calculated for 2-bromo-2-methylpropane to the k you calculated for 2-chloro-2-methylpropane. Explain any difference in rate constants based on a molecular understanding of an SN1 reaction.
9) If this experiment was done, (qualitatively) compare the rate of the secondary substrate 2-bromobutane with that of 2-bromo-2-methylpropane. Compare the rate of the secondary substrate 2-chlorobutane with that of 2-chloro-2-methylpropane. Explain any difference in rate constants based on a molecular understanding of an SN1 reaction.
10) References used (in proper ACS format)