  We show that a molecular BEC in a trap is stabilized against stimulated
dissociation if the trap size is smaller than the resonance healing length
$(\hbar^2/2mg\sqrt{n})^{1/2}$. The condensate shape determines the critical
atom-molecule coupling frequency. We discuss an experiment for triggering
dissociation by a sudden change of coupling or trap parameters. This effect
demonstrates one of the unique collective features of 'superchemistry' in that
the yield of a chemical reaction depends critically on the size and shape of
the reaction vessel.
