CKMMWY    CKMMWY    CKMMWY    CKMMWY    CKMMWY    CKMMWY    CKMMWY    
          **********************************************
                    **************************
                              ******

SUBROUTINE CKMMWY (Y, ICKWRK, RCKWRK, WTM)
Returns the mean molecular weight of the gas mixture given mass
fractions.

INPUT
Y(*)      - Real array, mass fractions of the mixture;
            dimension at least KK, the total species count.
ICKWRK(*) - Integer workspace array; dimension at least LENICK.
RCKWRK(*) - Real    workspace array; dimension at least LENRCK.

OUTPUT
WTM       - Real scalar, mean molecular weight of the mixture.
               cgs units, gm/mole