scotty 12 - Chemistry 13 Part 2 13.5 The Effect of...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemistry 13 Part 2 13.5: The Effect of Temperature on Reaction Rate The rates of chemical reactions are, in general, highly sensitive to temperature. A temperature increase generally results in an increase in k, which results in a faster rate. The modern form of the Arrhenius equation relates the rate constant (k) and the temperature in Kelvins (T) o K = Ae -Ea/RT The activation energy (E a ) is an energy barrier or hump that must be surmounted for the reactants to be transformed into products. o In 13.13, notice to get from the reactant to the product, the molecule must go through a high-energy intermediate state called the activated complex, or transition state. o Even though the overall reaction is energetically downhill (exothermic), it must first go uphill to reach the activated complex because energy is required to initially weaken the bonds. o The energy required to create the activated complex is the activation energy. The higher the activation energy, the slower the reaction rate (at a given temperature). The frequency factor (A) represents the number of times that the reactants approach the activation barrier per unit time. o The frequency factor represents the rate at which the reactant molecule vibrates (or rocks back and forth). With each vibration, the reactant approaches the activation barrier. However, approaching the barrier is not equivalent to surmounting it. Most approaches do not have enough total energy to make it over the barrier. The exponential factor is a number between 0 and 1 that represents the fraction of
Image of page 1

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

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ 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