The paper presents a quantitative theory for electron transfer reactions in solution, assuming minimal spatial overlap of the electronic orbitals of the reacting molecules in the activated complex. The theory involves calculating the free energy of all possible intermediate states, which are determined by minimizing their free energy subject to energy restrictions. The most probable intermediate state is identified, and its electrostatic contribution to the free energy of formation from the reactants is derived. This intermediate state can either reform the reactants or form a product state, with the overall reaction rate depending on which process is more probable. The theory is supported by kinetic data and provides a simple expression for the electrostatic contribution to the free energy of formation of the intermediate state.The paper presents a quantitative theory for electron transfer reactions in solution, assuming minimal spatial overlap of the electronic orbitals of the reacting molecules in the activated complex. The theory involves calculating the free energy of all possible intermediate states, which are determined by minimizing their free energy subject to energy restrictions. The most probable intermediate state is identified, and its electrostatic contribution to the free energy of formation from the reactants is derived. This intermediate state can either reform the reactants or form a product state, with the overall reaction rate depending on which process is more probable. The theory is supported by kinetic data and provides a simple expression for the electrostatic contribution to the free energy of formation of the intermediate state.