CHEMII: Chemical Dynamies and Energeties Dr. Mark Vaughan Capilano University Da
ID: 700894 • Letter: C
Question
CHEMII: Chemical Dynamies and Energeties Dr. Mark Vaughan Capilano University Day 4 Worksheet Potential Energy Profiles w hat is the difference between a transition state and a reaction intermediate? 2. Sketch a potential energy profile for a two-step reaction that forms an intermediate that is higher in energy than either the reactants or products, with the first step proceeding more slowiy than the second step and the overall process being exothermic. Temperature dependence of reaction rates 3. Why do chemical reactions generally proced more quickly at higher temperatures? The Arrhenius equation 4. The Arrhenius equation is k Express this relationship as a linear equation by taking the natural logarithm (ie, In) ofboth sides. k=Ae s. Determine the activation energy for the following reaction.EA le CH,CHO)(g) CH4(g) + CO(g) coe) 0.011 0.035 0.105 0.343 0.789 T(K) 700 730 760 790 810 6 Determine the activation energy for the flashing of fireflies, given the following data. Note that the rate of flashing can be treated as a rate constant. TO300-15 Flashes per minute 9.0 12.2 16.2 TCC 21.0 25.0 30.0 298 303 7 A first order reaction has a rate constant of 3.46 x 10's at 298.0 K. If the activation energy is 50.2 kJmol, what is the rate constant at 350.0 K?Explanation / Answer
Ans 5
ln (k2/k1) = (Ea/R) x (1/T1 - 1/T2)
ln (0.035/0.011) = (Ea/8.314) x (1/700 - 1/730)
1.157 = (Ea/8.314) x 5.871 x 10^-5
Ea = 163848 J/mol = 163.848 kJ/mol