Galvanic Cells

• In electrochemistry, the chemical reactions involve movement of electrons
• There are two types of electrochemical cells: galvanic cells and electrolytic cells
• Galvanic cells involve spontaneous reactions that generate electricity whereas electrolytic cells use electricity to drive nonspontaneous reactions
• Galvanic cells are constructed by separating the oxidation half-reaction from the reduction half-reaction and letting the electrons travel through a piece of wire
• The energy generated by the spontaneous redox reaction is used to produce electricity
• A galvanic or voltaic cell can be described by writing the components of the cell based on its construction
• A shorthand cell notation is often used to describe a galvanic cell. It uses the simplest form of each half-reaction. It starts with the anode to the cathode
• The components of the anode compartment (oxidation half-reaction) are written on the left hand side while the components of the cathode compartment (reduction half-reaction) are written on the right hand side. Electrodes appear at the far left and right of the notation
• A double vertical line is used to separate the half-cells and represent the salt bridge. The electrolytes in the solutions are written closest to the salt bridge. The electrolytes are separated from the electrodes by a single vertical line
• If there is no metal present to conduct the electrons from the anode to the cathode on either or on both half-cells, we use an inert electrode such as platinum or graphite
• A comma is used to separate the half-cell components present in the same phase
• In a heterogenous reaction (more than one phase), a vertical line is used to indicate a phase boundary
• An anode is where oxidation takes place while a cathode is where reduction takes place
• What are two ways chemical reactions can interact with electricity?

  1. Certain chemical reactions can create electricity.
  2. Electricity can make certain chemical reactions happen that would not happen otherwise.
• What information do we use to find out how likely a metal has a stronger pull for electrons?

  Standard Electrode Potentials
• What do we call the two pieces of metal in a galvanic cell?

  Electrodes
• What do we use in an electrolytic cell to make non-spontaneous reactions happen?

  Battery or batteries