The growth kinetics of the (100) face of sodium chloride crystals were measured in aqueous solution in the presence of a trace of lead(II) as a function of supersaturation and impurity concentration. The growth kinetic data are analyzed successfully using the kinetic model proposed by Kubota and Mullin [J. Crystal Growth 152 (1995) 203]. The value of the Langmuir constant determined from analysis of the data on growth kinetics was found to be in good agreement with the value obtained from direct adsorption experiments. The estimated value of the average spacing between the adjacent adsorption-active sites and the average distance between the neighboring impurity-adsorbed sites are also reported.