Question

INFORMATION reaction must also be perimental mea data are plotted in the sult means that the rate Because a reaction is faster at higher temperatures, the rate constant for the reaction m larger. The activation energy of a reaction can therefore be determined from experime surements of the rate constant at several temperatures. When the collected data are ple form In(k) vs T. as shown in Figure 2. a straight line is produced. This result means constant varies exponentially with 1/T, as given by the Arrhenius equation. Figure 2 Plot of Ink) vs 1/T, where is the rate constant for the reaction and T is the temperature in Kelvin In k -15+ 0.0017 0.0018 0.0019 0.0020 MODEL 2 THE ARRHENIUS EQUATION k = Ae RT The constant A is referred to as a frequency factor, and is determined by how often molecules col. lide when the concentrations are IM, and whether the molecules are properly oriented when they collide. A is the value that the rate constant would have if all the molecules had enough energy to react, e.g., when the activation energy E=0 or the Kelvin temperature T is very large. KEY QUESTIONS 7. Since the gas constant R has units of J/mol K, what are the units of E?! 316 Chapter 13: Chemical Kinctio

Answer 1

o La and they su. En will have unit of RT. En = Jmollys x X - sber smop!) Kadetilen g En' gets langer Eale' gets langer. 0 hence and k become smaller become so è tally smaller.. with eherse of Ea. a sn k wil deurere A from the free As I inore Ealpy wice deoses. . Hore e talpy will increse. su, k will also increya So, with increnity to, k win also increse,

6 Catalyst decrese the activation energy of the recetion. © It won't doesn't have any effect on free encyf of a recetion. ② It will alter the mechanistic pathway of the reaction. @ # won't effect the stoichiomeling of a reaction, 6 The rate of rate limiting step is much fester in they retea case of catalyzed reaction, than the unatalyzed (without the catalyst) rectin.