This paper deals with the temperature stabilization of a large class of continuously stirred tank chemical reactors, We design state feedback controllers, and we show their ability to globally stabilize the temperature at an arbitrary set point in spite of uncertainties on the kinetics, Furthermore, it is also shown that these controllers can handle input constraints along the closed-loop trajectories in some instances, For the implementation purpose, we design a robust state observer for the case of partial state measurement, and we prove that its incorporation in the feedback loops does not impair the nominal stabilization properties of the controllers.