Galvanic Cells (aka Voltaic Cells)

What is the set-up of galvanic cells?

Two half reactions that are connected by a salt bridge.

What is the importance of separating each half reaction?

If the metals were put in the same container the reaction would still occur, but it would be very difficult, if not impossible, to harness the energy of the red-ox reaction.

By putting a metal with a different charge in each half reaction and surrounding the metals with an electrolytic solution connected by a salt bridge, ion exchange can partially occur. The circuit is completed by connecting the metals with a wire. Then, the electron transfer through the wire can in turn be put to work, e.g. interspersing a motor or a light bulb.

What is the $\Delta$G of galvanic cells?

-$\Delta$G, i.e. the reaction is $spontaneous$.

What direction do electrons flow?

From the anode to the cathode.

Label the various parts of the galvanic cell:

Figure 33.2: The Galvanic Cell.

1. Anode side	4. e$^{-}$ flow (in both directions)
2. Cathode side	5. Energy being put to work
3. Salt bridge