The time-dependent approach to reactive scattering is applied to the study of the collinear collisions for the LiH++H system. The reaction LiH++H --> H-2+Li+ is adiabatically confined to the ground electronic state of the LiH2+ system and is highly exoergic (similar to4.2 eV). However, despite the strong energetic gain, the present calculations show that the reactive component is only a negligible outcome of the encounters while the simple inelastic scattering process and the collision-induced dissociation dominate the dynamics. The binding energy of the LiH+ reagent molecule is so weak that the threshold of the triatomic dissociation channels becomes open at a collision energy of only a few tenths of an electronvolt. The total dissociation probabilities are obtained via an accurate computation of all the possible bound-to-bound transition probabilities (reactive and nonreactive) using the quantum time-dependent approach described herein.