Final answer:
The electrolysis of brine, a concentrated solution of salt water (NaCl), produces three products: chlorine gas (Cl₂), hydrogen gas (H₂), and sodium hydroxide (NaOH). Chlorine is produced at the anode, while at the cathode, water is reduced to produce hydrogen gas and hydroxide ions, which combine with sodium ions to form sodium hydroxide.
Step-by-step explanation:
A major source of chlorine gas (Cl₂) is the electrolysis of brine, which is concentrated salt water (NaCl). Through this process, two other products result from the electrolysis apart from chlorine gas: hydrogen gas (H₂) and sodium hydroxide (NaOH).
During the electrolysis of brine, at the anode, chloride ions (Cl⁻) are oxidized to produce chlorine gas. At the cathode, instead of sodium ions being reduced to form sodium metal, water molecules are reduced due to their more favorable reduction potential, leading to the production of hydrogen gas and hydroxide ions (OH⁻). These hydroxide ions then combine with sodium ions (Na⁺) present in the solution to form sodium hydroxide. Therefore, the overall reactions at the electrodes during the electrolysis of brine are:
It's important to note that electrolysis of brine produces these substances without forming elemental sodium, which differs from the electrolysis of molten sodium chloride where sodium metal is produced. The byproduct sodium hydroxide has several applications, including being an ingredient in many cleaning agents, while the hydrogen gas produced has potential uses as a clean fuel.