The electrode potential becomes equal to the standard electrode potential when the reactants and products concentration ratio is

equal to 1

The electrode potential becomes equal to the standard electrode potential when the reactants and products concentration ratio is equal to 1.

This is because the standard electrode potential (E°) is defined as the electrode potential when the reactants and products are at their standard state, which is typically defined as a concentration of 1 M for solutes. When the concentration ratio of the reactants and products is 1, it means that the concentrations of the reactants and products are at their standard state, resulting in the electrode potential being equal to the standard electrode potential.

Therefore, the correct answer is (1) equal to 1.