ABSTRACT
A linear stability analysis of an isothermal quiescent solution of a model for a dissociating gas of infinite extent which is in chemical quasi-equilibrium, with its species and thermal fluxes proportional to each other, shows it to be identically stable for all temperatures. Then a longitudinal-planform nonlinear stability analysis of a Rayleigh- Bénard problem of a layer of such fluid satisfying the additional chemical quasi-equilibrium condition of the substantial derivatives of temperature and species, also being proportional with the same constant, demonstrates the occurrence of stable roll-type convection upon being heated from either below or above, the latter a chemically-driven instability that would not occur for nondissociating fluids.
