FDEP Drinking Water Operator C Practice Exam 2026 - Free Drinking Water Operator Practice Questions and Study Guide

When pure gas chlorine is added to water, it undergoes a chemical reaction that results in the formation of hydrochloric acid and hypochlorous acid. This addition of chlorine introduces a strong acid component into the water, which leads to an increase in the concentration of hydrogen ions (H+). As the concentration of hydrogen ions increases, the pH of the water decreases, indicating a more acidic solution. Therefore, the pH is lowered when chlorine is dissolved in water. Understanding this reaction is critical for water treatment processes, as it affects the water chemistry and can have implications for disinfection efficiency and overall water quality management.