LI-SOLUTION( HYDRATION IN CONCENTRATED AQUEOUS)

Neutron diffraction experiments were carried out on aqueous solutions of lithium chloride in heavy water at three concentrations-14, 3.6 and 1 molal. The first-order isotopic difference method was applied to th e lithium ions, and structural results were obtained for the Li+ hydra tion: the Li-O and Li-D near-neighbour distances in the first hydratio n shell remain the same at 1.95(3) and 2.5(5) Angstrom over the concen tration range studied. However, there is an increase in coordination n umber from 3.2 at 14 molal to approximate to 6.5 at 1 molal. There is also evidence for a relatively weak second hydration shell, which beco mes displaced to larger distances at lower concentrations.