This paper investigates steady and unsteady magnetohydrodynamic chemical kinetic exponent of free convective slip flow in a vertical channel filled with porous medium. The Navier slip and Newtonian heating at the plates were taken in to consideration. The governing equation were transformed from dimensional to non -dimensional form using dimensionless quantities, the steady state solution is obtained using Homotopy Perturbation Method (HMP), unsteady state solution was obtained through numerical approach refer to implicit finite difference scheme. The effects of various flow parameters entering into the problem such as Darcy number, Hartmann number, Navier slip parameter chemical reaction parameter, chemical kinetic exponent, local Biot number, as well as activation energy parameter with difference ratio were discussed with the aid of line graphs. It is found that greater values of chemical kinetic exponent (m) significantly improve the temperature and velocity gradients respectively in which the fluid velocity and temperature is higher at Biomolecular type of chemical reaction compare to that of Arrhenius and Sensitized. On the hand, Darcy number is seen to improve the fluid velocity. Furthermore, Comparison has been made for steady state and unsteady solution which shows excellent agreement.