Chapter 6 Self Test

What Type of Reaction is Taking Place?


Three species were found in a CSTR. The following concentration data were obtained as a function of temperature. The initial concentration of the single reactant, A, was the same at all temperatures. Both B and C are products.

CA0 = 2moles/dm3

Run
T (oC)
CA (mole/dm3)
CB (mole/dm3)
CC (mole/dm3)
1
30
1.7
0.01
0.29
2
50
1.4

0.03

0.57
3
70
1.0
0.1
0.90
4
100
0.5
1.25
1.25
5
120
0.1
1.80
0.1
6
130
0.01
1.98
0.01

Explain the above data, what type of reaction is taking place, independent, complex, series or parallel ?

Hint 1: What are the trends?

Hint 2: What do the trends suggest?

Full Solution


 

 

 

 

 

 


Hint 1

Observations

            At low temperatures

                        1)   Little conversion of A

                        2)   Little B formed

                        3)   Mostly C formed (but not too much because of the low conversion - 15 to 30% - of A)

            At high temperatures

                        1)   Virtually complete conversion of A

                        2)   Mostly B formed

    Back to Problem

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hint 2

Data suggest 2 reactions

Back to Problem

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Solution

Observations

            At low temperatures

                        1)   Little conversion of A

                        2)   Little B formed

                        3)   Mostly C formed (but not too much because of the low conversion - 15 to 30% - of A)

            At high temperatures

                        1)   Virtually complete conversion of A

                        2)   Mostly B formed

   

Data suggest 2 reactions

                            

Reaction (1) is dominant at high temperatures

            with

Reaction (2) is dominant at low temperatures

Back to Chapter 6