Page 104 - Introduction to chemical reaction engineering and kinetics

86 Chapter 4: Development of the Rate Law for a Simple System

1014 k/cm3 molecule-’ s-l
Ether 2 4 0 K 2 9 8 K 3 3 0 K 3 5 0 K 4 0 0 K

diethyl 17.0 38.1 55.8 66.1 98.6
di-n-propyl 25.8 58.2 75.3 114 130
90.0
v
68.9
36.0
di-n-butyl
89.7
153
“O-v
0 4-20 Nowak and Skrzypek (1989) have measured the rates of decomposition separately of (1)
Determine the Arrhenius parameters A and EA for each diether and specify the units of each.
NbHCOs (A) (to (N&)zCOs), and (2) (NH&C03 (B) in aqueous solution. They used an
open, isothermal BR with continuous removal of gaseous products (CO2 in case (1) and NH3
in (2)) so that each reaction was irreversible. They measured CA in case (1) and cB in case (2)
at predetermined times, and obtained the following results at 323 K for (1) and 353 K for (2).

lo-Q/s lOc,Jmol L-l locB/mol L-’

0 8.197 11.489
1.8 6.568 6.946
3.6 5.480 4.977
5.4 4.701 3.878
7.2 4.116 3.177
9.0 3.660 2.690
10.8 3.295 2.332
12.6 2.996 2.059
14.4 2.748 1.843
16.2 2.537 1.668
18.0 2.356 1.523

(a) Write the chemical equations for the two cases (H20 is also a product in each case).
(b) Determine the best form of the rate law in each case, including the numerical value of the
rate constant.