The table shows the variation of the rate constant with temperature for the first-order reaction. → 2N2O(g) 2N2O4(g) + O2(g) Determine graphically the activation energy for the reaction. Be sure your answer has the correct number of significant digits. T(K) k (우) 310. 1.57 10 320. 5.95 x 10 -4 330. 2.27 10 -4 340. 6.83 x 10 -3 350. 2.16 × 10 Note: Reference the Fundamental constants table for additional information. kJ mol Π

Gaseous azomethane (CH3N2CH3) decomposes to ethane and nitrogen when heated: CH3N2CH3(g) CH3CH3(g) + N2(g) The decomposition of azomethane is a first-order reaction with k = 3.6 104 s1 at 600 K. (a) A sample of gaseous CH3N2CH3 is placed in a flask and heated at 600 K for 150 seconds. What fraction of the initial sample remains after this time? (b) How long must a sample be heated so that 99% of the sample has decomposed?

11.32 The following experimental data were obtained for the reaction 2A + 3 B—C + 2D [A](mol L 1) [B](mol L ’) Rate = A(C]/Af (mol L-1 s-1) 0.127 0.15 0.033 0.127 0.30 0.132 0.255 0.15 0.066 Determine the reaction order for each reactant and the value of the rate constant.

(Section 11-5) A rule of thumb is that for a typical reaction, if concentrations are unchanged, a 10-K rise in temperature increases the reaction rate by two to four times. Use an average increase of three times to answer the questions below. (a) What is the approximate activation energy of a typical chemical reaction at 298 K? (b) If a catalyst increases a chemical reactions rate by providing a mechanism that has a lower activation energy, then what change do you expect a 10-K increase in temperature to make in the rate of a reaction whose uncatalyzed activation energy of 75 kJ/mol has been lowered to one half this value (at 298 K) by addition of a catalyst?