What needs to happen for an electrochemical reaction to occur?

For an electrochemical reaction to occur, it is essential for the cathode and anode to be connected. This connection allows for the flow of electrons between the two electrodes, which is fundamental to how electrochemical cells generate electrical energy. In a galvanic cell, for example, a spontaneous redox reaction takes place in which oxidation occurs at the anode and reduction takes place at the cathode. The movement of electrons from the anode to the cathode through an external circuit creates an electric current, which is the desired outcome of the electrochemical reaction.

While heating reactants, having a saturated solution, or using a catalyst may influence reaction rates or the nature of reactions, they are not strictly necessary for an electrochemical reaction to take place. The essential requirement is the establishment of a conductive path allowing electrons to move from the anode to the cathode, thereby driving the overall electrochemical process.