Chapter 9: Reaction Mechanisms, Pathways, Bioreactions and Bioreactors

Professional Reference Shelf

Example RE9.6-1: Construct a Lineweaver-Burk Plot for Different Oxygen Concentrations

    Construct a Lineweaver-Burk plot for this system in which each line corresponds to a different oxygen concentration. Also discuss the effect of total gas pressure of fixed oxygen concentration on the rate of this liquid-phase reaction,rp. (Hint: Recall Henry's law.)  
       
    Solution
We first invert Equation (R7.4-7) to find		  
       
   

IMAGE 07eq62.gif

(RE7.4-1.1)
       
    From Equation (CD7-6.1) we see that changes in the oxygen concentration will only affect the intercept of a Lineweaver-Burk plot. As the oxygen concentration increases, the intercept decreases.

Assuming equilibrium between oxygen in the gas phase and oxygen in the liquid phase, we obtain the following relationship (Henry's law):		  
       
   

IMAGE 07eq63.gif

 
    image 07eq64.gif







(RE7.4-1.2)
    At high pressures,  
       
   

IMAGE 07eq65.gif

 
       
    At low pressures,  
       
   

IMAGE 07eq66.gif

 
       
    Figure RE7.4-1.1 shows the a Lineweaver-Burk plot for various oxygen concentrations, and Figure RE7.4-1.2 shows the reaction rate as a function of total pressure for a fixed mole fraction of oxygen.  
       
   

Figure RE7.4-1.1



Figure RE7.4-1.2