Differences Between Galvanic & Electrochemical

Voltaic Cells

• Both galvanic and electrochemical cells are voltaic cells. This means they utilize a spontaneous chemical reaction to move an electrical current through an external circuit. Voltaic cells are responsible for the batteries that we use to power electronic devices today. Both galvanic and electrochemical cells are used in batteries, but they vary slightly.

Galvanic Cells

• Galvanic cells are comprised of two containers joined by a salt bridge. One of the containers holds a silver nitrate solution, called a cathode or positively charged solution. The other holds a copper nitrate solution, known as an anode or negatively charged solution. Separately, the containers remain neutral, not having the chemical reaction they need to create energy. The salt bridge between the containers allows ions to enter or leave each container. As ions flow from the cathode to the anode, electricity is produced.

Electrochemical Cells

• Electrochemical cells are created by combining copper sulfate and zinc sulfate solutions in two containers, similar to galvanic cells. A salt bridge acts as a conductor between them allowing electrons to transfer from the zinc to the copper to create an electrical current which can be used to power electrical devices. Electrochemical cells are very similar to galvanic cells, but one major difference separates them. Electrochemical cells can translate an electrical current as described above, which makes them voltaic cells. However, they can also take the form of electrolytic cells, which do not create spontaneous chemical reactions, but require externally supplied electrical currents to create the reaction.

Electrolytic Cells

• In an electrolytic cell, the containers are set up very similarly to a galvanic cell, except that the cathode container is negatively charged and the anode container is positively charged. Molten sodium chloride is an example of an electrolytical cell or electrolysis. The reaction creates an electrical current that splits the compound into its two elements so that it changes from sodium chloride into sodium and chloride cells. While galvanic cells use energy created in a spontaneous reaction to create electricity, electrolytic cells use electricity to drive a chemical reaction in an opposite direction than a galvanic cell would.