(H, Li)Br and LiOH Solvation Bonding Dynamics: Molecular Nonbond Interactions and Solute Extraordinary Capabilities

We resolved the O:H-O bond transition from the mode of ordinary water to its hydration in terms of its phonon stiffness (vibration frequency shift Δω), order of fluctuation (line width), and number fraction (phonon abundance), f_x(C) = N_hyd/N_total. The f_x(C) follows f_H(C) = 0, f_Li(C) ∝ f_OH(C) ∝ C, and f_Br(C) ∝ 1 - exp(-C/C₀) toward saturation with C being the solute concentration. The invariant df_x(C)/dC suggests that the solute forms a constantly sized hydration droplet without responding to interference of other ions because its hydrating H₂O dipoles fully screen its electric field. However, the number inadequacy of the highly ordered hydration H₂O dipoles partially screens the large Br^-. The Br^- then interacts repulsively with other Br^- anions, which weakens its electric field and the f_Br(C) approaches saturation at higher solute concentration. The consistency in the concentration trend of the f_LiBr(C), the Jones-Dole viscosity η(C), and the surface stress of LiBr solution clarifies their common origin of ionic polarization. The resultant energy of the solvent H-O exothermic elongation by O: ⇔ :O repulsion and the solute H-O endothermic contraction by bond-order deficiency heats up the LiOH solution. An estimation of at least 0.15 eV (160% of the O:H cohesive energy of 0.1 eV) suggests that the H-O elongation is the main source heating up the solution, while the molecular motion, structure fluctuation, or even evaporation dissipates energy caped at 0.1 eV.