galvanic+cells

Galvanic Cells
A galvanic cell is essentially a battery. It will typically use metals as electrodes, immersed in electrolyte solutions containing the corresponding metal ions.

A typical galvanic cell is shown in the diagram below: There is always a reduction half-reaction and an oxidation half-reaction occurring, each in its respective "cell" (beaker, in this case).

The metal undergoing reduction is called the **cathode**.

The metal undergoing oxidation is called the **anode**.

Each cell will produce a //cell potential//, measured in volts, and the sum of the two cells is called the **standard cell potential**.

In the example above, the standard cell potential is the sum of 0.34 V and 0.76 V, with a total of 1.10 V.

Salt Bridges
A salt bridge is a device that connects two cells in a galvanic cell. Its purpose is to create a closed circuit and to allow electron flow to occur from one electrode to the other.

The salt bridge is a tube or porous boundary between the two cells, and as its name implies, is filled with salt - positive and negative ions. As the redox reaction proceeds, the salt's ions will migrate, which keeps the circuit running.

Try this virtual galvanic cell builder.
Here is an animation of a galvanic cell in operation.