We have employed molecular beam techniques to investigate the molecular trapping and trapping-mediated dissociative chemisorption of propane on Ir(110) at low beam translational energies, E(i) less than or equal to 5 kcal/mol, and a wide range of surface temperatures, T-s, from 85 to 1200 K. At E(i) = 1.6 kcal/mol and T-s = 85 K, molecular propane is physically adsorbed on Ir(110) with a trapping probability of 0.94. At E(i) = 5 kcal/mol and T-s = 85 K the trapping probability drops to 0.86. For T-s > 150 K propane is dissociatively chemisorbed, with initial probabilities of dissociative chemisorption decreasing with increasing surface temperature from 150 to approximately 700 K. At surface temperatures from 700 to 1200 K, the initial probability of dissociative chemisorption maintains the essentially constant value of 0.16. These observations are explained within the context of a kinetic model which includes both C-H and C-C bond cleavage. Below 500 K propane chemisorption on Ir(110) arises essentially solely from C-H bond cleavage, an unactivated mechanism (with respect to a gas-phase energy zero) for this adsorption system, which accounts for the decrease in initial probabilities of chemisorption with T-s. With increasing T-s, however, C-C bond cleavage, the activation energy of which is greater than the desorption energy of physically adsorbed propane, increasingly contributes to the measured probability of dissociative chemisorption. The activation energies? referenced to the bottom of the physically adsorbed molecular well, for C-H and C-C bond cleavage for C3H8 on Ir(110) are found to be E(r,CH) = 5.3 +/- 0.3 kcal/mol and E(r,CC) = 9.9 +/- 0.6 kcal/mol, respectively, while the desorption activation energy of propane from Ir(110) is approximately 9.5 kcal/mol. These activation energies are compared to activation energies determined recently for ethane and propane adsorption on Ir(111), and ethane activation on Ir(110).