Kinetics Solutions: #9

9.* (1994 F 5) The thermal decomposition of acetaldehyde (CH3CHO) was measured at two temperatures. At T=700K, the rate of this second-order process was 0.011 (mol/L)-1s-1and at T=760K it was 0.105 (mol/L) -1s-1.

Use this data to estimate the activation energy Ea and the pre-exponential factor A given that the universal gas constant R has the value 8.314 JK-1mol-1. State clearly the units of Ea and A.

Arrhenius equation:

State 1: k1 = 0.011 M-1 s-1

T1 = 700 K

State 2: k2 = 0.105 M-1 s-1

T2 = 760 K

(1)

(2)

Use state 1 data to calculate A: