A study was made of the rate of gas adsorption by activated carbon in terms of the functional dependence of the pseudo first order adsorption rate constant. Benzene was used as the adsorbate vapor and a packed bed column of a Pittsburgh activated carbon as the adsorbent. Benzene at a concentration of 2 × 10 −6 g/cm 3, equivalent to a relative pressure of 0·005 at 25°C, was flowed into the carbon bed at superficial linear velocities ranging from 2 to 50 cm/sec. The time at which 1% of the inlet concentration appeared in the exit stream of the bed was the breakpoint time. By applying the Wheeler adsorption kinetic equation to the experimental plot of breakpoint time vs bed weight pseudo first order adsorption rate constants at various linear velocities were determined. Using a presumed mathematical model and an overdetermined set of six equations the Univac 1108 computer provided the coefficients for an expression showing the dependence of the adsorption rate constant on the linear flow velocity.