Chlorine is commonly used for which of the following tasks in water treatment?

Chlorine is primarily known for its role as a disinfectant in water treatment processes. Its effectiveness in killing bacteria, viruses, and other pathogens makes it a vital component in ensuring safe drinking water. By introducing chlorine into the water supply, treatment facilities can significantly reduce the risk of waterborne diseases.

Disinfection is crucial for maintaining public health and is often one of the final steps in the treatment process after the removal of larger particles through processes like flocculation and filtration. Chlorine not only eliminates harmful microorganisms but also leaves a residual level in the distribution system, providing ongoing protection against potential recontamination.

Other options, such as flocculation and filtration, involve different processes altogether. Flocculation deals with the aggregation of particles to form larger flocs that can settle out, while filtration is the physical separation of particles from water. Neutralization refers to balancing the pH of water, often through the use of acids or bases, and is separate from the disinfection process. Each of these actions serves specific purposes in water treatment, but chlorine's role as a disinfectant is paramount in ensuring the microbiological safety of drinking water.