During the electrolysis of concentrated aqueous sodium chloride solution, commonly known as the chlor-alkali process, which gas is liberated at the anode?

💡 Solution & Explanation

In the chlor-alkali electrolysis process, chloride ions are oxidized at the anode to produce chlorine gas, while hydrogen ions are reduced at the cathode to yield hydrogen gas, leaving behind an aqueous solution of sodium hydroxide. Oxygen is not the primary anodic product due to lower oxidation potential requirements for chloride ions under concentrated conditions. Sodium metal is not deposited because reduction of water occurs preferentially over sodium ions in aqueous media. The process is foundational for producing industrial alkali and chlorine derivatives.