The nucleophile was observed to follow a zeroth order

Info icon This preview shows pages 2–5. Sign up to view the full content.

alkyl halide, was concluded to follow a first order rate law. The nucleophile was observed to follow a zeroth order rate. From these observations, it can be concluded that the transition state of the rate-limiting step is unimolecular. It is predicted that the producted Experimen t [ t BuCl] 0 (M) [OH - ] 0 (M) Time (S) Reaction Rate (M/s) Rate Constant (s -1 ) 1 0.1 0.03 49.49 2.02 x 10 -4 2.13 x 10 -3 2 0.1 0.06 148.78 1.34 x 10 -4 1.50 x 10 -3 3 0.1 0.09 223.94 1.34 x 10 -4 1.59 x 10 -3
Image of page 2

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

formed are form tert-butanol and hydrochloric acid. Please refer to the final page for the reaction mechanism. 4. Table 3: Comparison of reaction rates of experiments with varying temperatures. Figure 1: Linear plot of ln (k) vs. 1/T to show the effect of temperature on reaction rate. 0 0 0 0 0 0 0 -9.6 -8.4 -7.2 -6 -4.8 -3.6 -2.4 -1.2 0 f(x) = - 11410.36x + 31.65 Effect of Temperature on Reaction Rate 1/T (K-1) ln (k) This Arrhenius plot has a slope of -11410 and has a y-intercept of y = 31.648. The activation energy is 94.825 kJ/mol. Based on the data from Figure 1, it appears that temperature and reaction rate have a positive relationship. Larger temperatures would have smaller inverses (lower x-axis values) and larger reaction constants (k) have larger values when their natural logarithm is calculated (greater y-axis values). Thus, as the inverse of temperature decreases, which means temperature is increasing, the natural logarithm of the reaction constant will increase, thus increasing reaction rate. Note that the magnitude of the natural logarithm of the rate constant increases as the inverse of temperature increases. Because of this trend, the activation energy will increase when there are smaller rate constants and lower temperatures. Calculation: Y value at x value of 0.00340 K -1 : y = -11410 (0.00340) + 31.648 = -7.146 -RT (ln k – ln A) = E a Experiment Temp (K) Reaction Time (s) Reaction Rate (M/s) Rate Constant (s - 1 ) 1 294 49.49 2.02 x 10 -4 2.02 x 10 -3 6 (Trial 1) 284 612.85 1.63 x 10 -5 1.63 x 10 -4 6 (Trial 2) 284 630.25 1.59 x 10 -5 1.59 x 10 -4 7 (Trial 1) 304 47.53 2.10 x 10 -4 2.10 x 10 -3 7 (Trial 2) 304 42.50 2.35 x 10 -4 2.35 x 10 -3
Image of page 3
= -8.314 J/mol/K x 294 K (-7.146 – 31.648) = 94824.795 J/mol = 94.825 kJ/mol 5. Experiment 8 had a solvent composition of 80% water to 20% acetone and a rate constant of 3.00 x 10 -3 M/s. Experiment 5 had a solvent composition of 70% water to 30% acetone and its rate constant was smaller, with a value of 1.62 x 10 -3 M/s. Experiment 9 had a solvent composition of 60% water to 40% acetone, and its rate constant was even smaller, with a value of 8.37 x 10 -4 M/s. This showed that the rate constant lowered as the difference between water and acetone concentrations in the solvent became smaller. This
Image of page 4

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 5
This is the end of the preview. Sign up to access the rest of the document.
  • Fall '09
  • POTVIN
  • 20%, 40%, 30%, 5 m/s, 4 m/s

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern