Electrolytic Cells

Electrolysis

Electrolysis uses an electrolytic cell to make a nonspontaneous redox reaction occur.

Spontaneous redox reactions can generate a voltage. But an electric current can be run through a cell to make the reverse (nonspontaneous) redox reactions occur.

Voltaic cell vs. Electrolytic

Voltaic cells create electricity. Electrylytic cells use electricity. In other words, voltaic cells are batteries and electrolytic cells use batteries

Uses of Electrolysis

Purifying or refining metals

Cations of molten salts are reduced to make very pure metals.

Example: Al2O3 (l) + 3C(s) → 4Al(l) + 3CO2 (g)

Metal plating

A thin layer of metal is formed around the cathode

Ag+(aq) + e— → Ag(s) (formed at the cathode)

Creation of gases

You can split water into hydrogen and oxygen gas.

You can split brine (concentrated saltwater) into chlorine gas, hydrogen gas, and sodium hydroxide.