DE_Chem_4.4_Electrochemistry

Electrolysis of water (2H₂O→2H₂+ O₂) is a reaction (think of the different type of reactions we have studied)

In an electrochemical cell, must be present. Oxidation occurs (electrons are released) at a location referred to as the . Reduction occurs (electrons are gained) at a location referred to as a . The anode and cathode must be so that electrons and ions can between them.

move through wires from one electrode to the other. Then take over and move through the solution to complete the circuit

This image is an example of a(n) cell.

This is an example of a(n) cell.

There are two types of electrochemical cells. Voltaic cells use chemical reactions to electricity, and electrolytic cells use electricity to chemical energy

Electrons have potential energy. This potential energy varies depending on an electron’s in a circuit. Potential energy also depends on the reaction taking place at each electrode. Cell potential is the in electric potential energy between the two electrodes in a cell. This quantity is measured in (V).

Standard reduction potential (E°), in units of volts, measures a substance’s ability to gain electrons at standard conditions of temperature and pressure. The standard reduction potential is also called the because it can be used to describe all of the reactions that occur in a cell. The standard electrode potential of an oxidation half-reaction is to the standard electrode potential of the reduction reaction.

In a voltaic cell, electrons are transferred through an external pathway (wire), from the anode to the cathode. Ions then are transferred through an pathway.

An electrolytic cell involves a non-spontaneous oxidation-reduction reaction. Energy must be for this reaction to proceed. An electrolytic cell uses energy, often in the form of a battery, to break down compounds and chemical energy in a process called .

In electrolytic cells, energy is converted to

In voltaic cells, energy is converted to energy.