Dive into the 2025 NY Wastewater Exam – Flush Away the Competition with Confidence!

When chlorine gas is added to water, a chemical reaction occurs that produces hypochlorous acid and hydrochloric acid. The equation representing this reaction is:

Cl2 + H2O ⇌ HCl + HOCl

In this process, chlorine (Cl2) reacts with water (H2O) to create two acids: hypochlorous acid (HOCl), which is a weak acid that has disinfectant properties, and hydrochloric acid (HCl), which is a strong acid commonly found in various applications, including wastewater treatment.

The formation of these specific acids is significant in contexts such as sanitation and disinfecting, as hypochlorous acid is primarily responsible for the antimicrobial activity. Understanding this reaction is crucial for wastewater treatment operators as it plays an essential role in the disinfection process.

The other choices mentioned involve acids that are not produced through the reaction of chlorine gas with water, as they pertain to entirely different chemical processes or compounds.