CHE 205
Homework Set 6 – Due Sept. 30th
This assignment is to be completed and submitted as a group.
1. F&R 4.46.
a) In Part (a), don’t derive an equation for  as the problem statement requests, but
rather assume nC0 = nD0 = nI0 = 0 (no products or inert in the feed), write the four
expressions for ni() [nA = nA0 – , nB = ...], then an expression for ntot ( = nA + nB
+ nC + nD), and then four expressions for yi [yA = nA/ntot, yB = ...], and finally the
equilibrium relation (... = 4.87). Also write an expression for fA, the fractional
conversion of A, in terms of those other variables. Enter the expressions into an
E-Z solve program.
b) In Part (b), assume a basis of 100 mol of methanol fed (enter nA0 = nB0 = 100 in
the E-Z Solve program). Click “Solve.” Make your initial guess for  and all of
your initial guesses for the n’s 50 except the guess for ntot, which you should
make 200, and make your guess for fA and all of your guesses for the y’s 0.50.*
c) In Part (c), define values for nB0 (= 80) and nC (= 70) in your program, delete the
definition of nA0 from the program of Part (b), and rerun the program.
2.
F&R 5.12
3.
F&R 5.17
4.
F&R 5.30
5.
F&R 5.46. Complete and submit the workbook pages for this problem.
6.
F&R 5.62. Complete and submit the workbook pages for this problem. Instead
of using EZ Solve as shown in the workbook, use Excel to solve the problem.
(You should fill in the blanks in the EZ Solve section on p. 5-29 anyway – it will
help you set up your Excel file). Submit the Excel file using WebAssign. Submit
one file per group.
7.
F&R 5.65
*
When you are working with nonlinear equations, poor initial guesses can lead the program to
mathematically correct but physically impossible solutions, like negative mole fractions.