Massachusetts Wastewater Practice Exam

Sodium Metabisulfite is primarily used as a:

1. Oxidizing agent

2. Reducing agent

3. Chelating agent

4. Both oxidizing and reducing agent

The correct answer is: Reducing agent

Sodium Metabisulfite, often recognized for its chemical properties, serves primarily as a reducing agent in various applications, particularly in wastewater treatment and food preservation. As a reducing agent, it plays a crucial role in processes that require the removal of oxygen or the reduction of oxidation states of other substances. This characteristic is especially valuable in wastewater treatment, where it helps neutralize chlorine and other oxidizing agents, preventing potential damage to sensitive aquatic life. By donating electrons, Sodium Metabisulfite effectively reduces chlorination byproducts and maintains the necessary balance of chemicals in the treatment process. While it can have some oxidizing properties, its main function is as a reducing agent, aligning with its widespread classification in chemical processes. Understanding this fundamental role helps clarify its significance in environmental applications and industrial uses.