Hyper-Rayleigh or second harmonic Rayleigh scattering (HRS or SHLS) has been employed to measure equilibrium physical properties of molecules in solution. It has been utilized in our laboratory to obtain the dissociation constants of weak organic acids such as substituted benzoic and cinnamic acids in solution. Partition coefficient, supramolecular structure formation and stoichiometry, critical micelle concentration, and binding or association constant of a molecule with another molecule have all been measured by the HRS technique by us. We find that both the symmetry of the molecule and its concentration in the medium play an important role in finding new chemical applications of the technique.