Please note the following from the above figure:
- A polar solvent such as water molecules stabilizes the reactant, the transition state and the product in the “SN2” reaction, because of enhanced dipole-dipole interactions
- When “water” is used as a solvent, the “transition state” is stabilized to a greater extent than the reactant and the product.
- Thus, the reaction is accelerated in water compared with the rate observed in ethyl-acetate, which is a less polar solvent.
- Water is more capable than ethyl acetate in stabilizing ions, by both donating and accepting hydrogen bonds.
- Water acts a “catalyst” by decreasing the “activation energy”, since it reduces the energy of the transition state relative to that of the starting materials;
