Grote–Hynes theory is a theory of reaction rate in a

solution Solution may refer to: * Solution (chemistry), a mixture where one substance is dissolved in another * Solution (equation), in mathematics ** Numerical solution, in numerical analysis, approximate solutions within specified error bounds * Solu ...

phase. This rate theory was developed by James T. Hynes with his graduate student Richard F. Grote in 1980. The theory is based on the generalized Langevin equation (GLE). This theory introduced the concept of frequency dependent

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of t ...

for chemical rate processes in solution phase. Because of inclusion of the frequency dependent friction instead of constant friction, the theory successfully predicts the rate constant including where the reaction barrier is large and of high frequency, where the

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

over the barrier starts decoupling from

viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

of the medium. This was the weakness of Kramer's rate theory, which underestimated the reaction rate having large barrier with high frequency.

References

Physical chemistry {{physical-chemistry-stub