Unsteady/steady hydromagnetic natural convection heat and mass transfer flow characteristics of viscous reactive, incompressible and electrically conducting fluid in a vertical channel with Soret effect in the presence of uniform transverse magnetic field is studied. It is assumed that the chemical kinetics in the flow system is exothermic. The analytical expressions for the steady-state version of the problem has been derived for the temperature, concentration, velocity, skin friction, rate of heat transfer and rate of mass transfer using perturbation series method. The solutions for unsteady state temperature, concentration and velocity are obtained numerically using semi-implicit finite difference scheme. Numerical results are graphically discussed for various values of physical parameters embedded in the problem.