Used to disinfect drinking water

• A. Copper sulfate
• B. Halazone
• C. Chloroform
• D. Muriatic acid

Answer: (B)

Halazone is a chlorine-releasing tablet used to disinfect drinking water, especially in field or emergency situations. When dissolved, it releases chlorine that quickly inactivates microorganisms and can provide residual disinfection as the water sits, making it practical for portable purification.

Copper sulfate is mainly used as an algicide and pest control in water, not as a reliable disinfectant for drinking water. Chloroform is a solvent and a potential byproduct of chlorination, not something used to disinfect water. Muriatic acid (hydrochloric acid) is used to adjust pH or for cleaning, not for disinfection.