In: Chemistry
Given the following reaction and thermodynamic data, what is a reccomended temperature for a 1 L pilot scale reactor and how long (time) does it take for the reaction to take place?
CH3OCH2CH2CH2OCH2NH2 -> CH3OCH2CH2CH2OH + CH2=NH
Species |
CH3OCH2CH2CH2OCH2NH2 |
CH3OCH2CH2CH2OH |
CH2NH |
Hf (Kcal/mol) |
-91.15 |
-92.23 |
19.75 |
S (cal/mol/K) |
118.08 |
97.18 |
54.18 |
300 |
39.13 |
29.37 |
8.92 |
400 |
48.84 |
36.69 |
10.39 |
500 |
56.65 |
42.77 |
11.99 |
600 |
63.34 |
48.03 |
13.47 |
800 |
74.69 |
56.74 |
15.95 |
1000 |
82.87 |
62.98 |
17.87 |
1500 |
0 |
0 |
21.02 |
ΔHrxn (Kcal/mol) |
ΔSrxn (cal/mol/K) |
ΔGrxn (Kcal/mol) |
Kp |
18.67 |
33.28 |
8.69E+03 |
0.985534268 |
18.494 |
32.77367955 |
5.38E+03 |
0.993248201 |
18.292 |
32.31453957 |
2.13E+03 |
0.99785361 |
18.118 |
32.00460919 |
-1.08E+03 |
1.0009103 |
17.67 |
31.31834149 |
-7.38E+03 |
1.004656425 |
17.256 |
30.84797494 |
-1.36E+04 |
1.0068639 |
43.894 |
67.11038492 |
-5.68E+04 |
1.019230233 |
Kc |
A-forward (sec^-1) |
Ea(Kcal/mol) |
K-forward (sec^-1) |
0.001653304 |
2.10611E+14 |
53.09 |
4.40801E-25 |
0.001249683 |
2.80815E+14 |
52.914 |
3.42895E-15 |
0.001004382 |
3.51018E+14 |
52.712 |
3.18437E-09 |
0.000839549 |
4.21222E+14 |
52.538 |
3.06178E-05 |
0.000632018 |
5.61629E+14 |
52.09 |
3.295681283 |
0.000506726 |
7.02037E+14 |
51.676 |
3561.584427 |
0.000341966 |
1.05305E+15 |
78.314 |
4084.744896 |
Delta S+c (cal/mol/K) |
A-backward (sec^-1) |
K-backward (sec^-1) |
-24.11856204 |
45429261.35 |
9.50818E-32 |
-23.54895154 |
59940560.67 |
7.31917E-22 |
-23.10712731 |
74049093.99 |
6.7176E-16 |
-22.74613063 |
87957142.2 |
6.39344E-12 |
-22.17652012 |
114260467 |
6.70489E-07 |
-21.73469589 |
139369642.5 |
0.000707053 |
-20.93187498 |
531011737.2 |
0.002059767 |
The data shows that at 1500 degree Kelvin, Kp is the highest ( 1.01923) compared to reaction at all other temperatures. Even the delta G of the recation at 15000 K is most negative ( -5.68E+04) compared to reaction at other temperatures showing that reaction becomes most spontaneous at 1500 K [More negative the delta G - free energy of the reaction is, more spontaneous it is] So 1500 K is the temeprature at which reaction is spontaneous to its maximum
Kp = Kc (RT) ∆n
1.019230233 = 0.000341966 [(0.0821 L-atm/mole * K) (1500)]∆n
Upon solving =
2980.501667 = (0.0821 * 1500)∆n
2980.501667 = (123.15)∆n
log 2980.501667 = log (123.15)
3.474289 = ∆n * log (123.15)
= ∆n * (2.0904)
∆n = 1.662
So 1.662 moles of product is formed once reaction completes
Rate of forward reaction shows Kf = 4084.744896
meaning 4084.744896 moles of product are formed per second
So, formation of 1.662 moles of product takes (1.662 moles * 4084.744896 moles/sec = 4.0685 * 10-4 seconds)
So it takes 4.0685 * 10-4 seconds for the reaction to get completed.