[sandbeda]

I need to work out some equilibrium concentrations in terms of formality for the formation and dissociation of the adduct shown:

B2H6 + 2 THF <--->  2THFBH3

THFBH3 <--->  BH3 + THF

The delta G and Keq have been previously calculated (via computation), and my professor wants us to use an ICE-table.  I have worked the ICE-table this far:

          A2      +       2S <--->    2SA              SA  <--->    S     +     A
I          f                 mf              0                 0              0            0
C1      -af              -2af           +2af             +2af                       -2af
C2                        +2af          -2bf              -2bf           +2bf      +2bf
eq     f(1-a)       2f(2b-2a+m)   2f(a-b)          2f(a-b)       2bf         f(2b-2a+m)

where keq1 = 2.00853E-07, keq2 = 3.14017E-06, and m, a and b are simply coefficients.  By looking at the keq, we can see that 1>>b>a, and m>>b>a. 

I need to derive equations fo the equilibrium concentrations of each component in terms of formality f, by using the mole fractions (in Keq), to solve for a and b, and substitute them into the equations for equilibrium concentrations.  No matter what I do I can not seem to solve for a and b.  I can go into more detail if need be, or post a picture of my work, but can SOMEBODY HELP ME!