How does liquid chlorine affect the pH of water?

How does liquid chlorine affect the pH of water?

• A. It lowers the pH
• B. It raises the pH
• C. It has no effect on pH
• D. It stabilizes the pH

Answer: (B)

Liquid chlorine, when added to water, acts as a strong oxidizing agent and can significantly influence the pH level. The primary form of chlorine used is sodium hypochlorite, which dissociates in water to release hypochlorous acid. This process introduces hydrogen ions into the solution, thereby increasing the acidity and consequently lowering the pH. However, it is important to note that in typical operations, the introduction of chlorine itself leads to complex interactions that can affect the water chemistry. In most instances, when chlorine is added, it results in a decrease in pH. If the water has a buffer system, it may resist changes in pH to some extent, but chlorine does tend to create a more acidic environment. Therefore, recognizing that chlorine lowers pH is vital for water treatment processes, as operators must often make adjustments to mitigate significant pH fluctuations to adhere to regulatory standards and maintain optimal conditions for water quality.

Liquid chlorine, when added to water, acts as a strong oxidizing agent and can significantly influence the pH level. The primary form of chlorine used is sodium hypochlorite, which dissociates in water to release hypochlorous acid. This process introduces hydrogen ions into the solution, thereby increasing the acidity and consequently lowering the pH.

However, it is important to note that in typical operations, the introduction of chlorine itself leads to complex interactions that can affect the water chemistry. In most instances, when chlorine is added, it results in a decrease in pH. If the water has a buffer system, it may resist changes in pH to some extent, but chlorine does tend to create a more acidic environment.

Therefore, recognizing that chlorine lowers pH is vital for water treatment processes, as operators must often make adjustments to mitigate significant pH fluctuations to adhere to regulatory standards and maintain optimal conditions for water quality.