Twoeq7

Name: Twoeq7 - Chemical equilibrium - 3rd formulation
Source: Eberhart, J. G., 1986, J. chem. Educ. 63, 576.
Reference/s Shacham, M. 1989, Chem. Engng. Sci., 44(7), 1495
       
Model: 2 implicit equations, indep. variables x1 and x2
  Lower difficulty level
  Constraints: 0<=x1<=1
  Discontinuities: function undefined for x1=0.26667
  Initial estimates:1. x1=0, x2=-1; 2. x1=0, x2=1; 3. x1=0.5, x2=0.1; 4. x1=0.5, x2=-0.1;
       
Solved by Shacham, M., POLYMATH 5.1, build 19,April 2, 2001
       
Model Eqs. Chemical Equilibrium |POLVER05_1

EXCEL FILE 

f(x1) = a-((c+2*x1)^2*(a+b+c-2*x1)^2)/(x2)-x1 #

TEXT FILE 

f(x2) = x2-kp*P^2*(b-3*x1)^3 #

POLYMATH FILE 

a = 0.5 #
  b = 0.8 #
  c = 0.3 #
  kp = 604500 #
  P = 0.00243 #
  x1(0)=0
  x2(0)=-1
       
Variable/function values Variable Value f(x)
  x1 0 0.7304
  x2 -1 -2.82759017
       
Solution 1 Variable Value f(x)
  x1 0.6003231171445 0.0000E+00
  x2 -3.57990244801 2.2204E-15
       
Solution 2 Variable Value f(x)
  x1 0.0586545710394 -1.0408E-16
  x2 0.86743788245 -2.2204E-16
       
Additional information Modified version of problem Oneeq11. Convergence
  to solution 1 from initial guesses 1 and 4, convergence
  to solution 2 from initial guesses 2 and 3.