CHEM 113C, Spring 2009, Problem Set 3. DUE Friday May 24 in class.
Problem 1. (100 points) For the reaction
2 I + Ar Ø I2+ Ar
you have the following data.
Ar 2. 103sec 4. 103sec 6.103sec 8. 103sec 10. 103sec
0.002 8.45 ×10−68.7 ×10−68.9 ×10−69.05 ×10−69.15 ×10−6
0.004 8.53 ×10−68.96 ×10−69.19 ×10−69.34 ×10−69.44 ×10−6
0.006 8.77 ×10−69.19 ×10−69.39 ×10−69.52 ×10−69.6 ×10−6
The table gives the I2 concentrations in mol/liter at the time listed in the headings. The first row is for an Ar concentration of
0.002 mol/liter, the second for 0.004 mol/liter Ar etc.
The initial concetration
I(0) = 2* 10-5mol/liter
I2H0L= 0
1a. Assume that the reaction is pseudo second order and write the rate equation and the mass balance.
dI
dt =-kAr I2
Denote
kp= Ar k
and determine kp by fitting the data in the table. Test the fit by calculating the percentage deviation of the fit to the data.
1b. Calculate kp for all three Ar concetrations and test whether it satisfy Eq. 1. Calculate k.
Problem 2: Consider the reactions
A ØB rate constant k1
BØC rate constant k2
2a. (30 points) Prove that B(t) has a maximum.
2b. (30 points) Find the formula for the time the maximum is reached.
Problem 3: (50 points)
Write the rate equations and the mass balance for the follwing reactions:
A Ø2B
B+CØD+E
E+AØF+C
E+B ó G+H
For problem 1: If you do not use Mathematica explain how you would do the calculations. Give the equation and explain
the procedure.