Water is often treated with chlorine to:
A. Increase oxygen content
B. kill germs
C. remove suspended particles
D. remove hardness

Hint: Chlorine has got various uses as disinfectant. Even in case of water it is used. The reason for treating water with chlorine depends upon the various properties of chlorine. Therefore we need to explore each property of chlorine so as to answer this question.

Step by step answer:
To protect drinking water from disease-causing organisms which are known as pathogens, water suppliers often add a disinfectant. This disinfectant is in fact chlorine, which is added to the drinking water.
Hence we can say that water is often treated with chlorine to kill germs. Therefore the answer to this question is Option B.
The process of treating water with chlorine is known as chlorination. Water chlorination is defined to be a process in which chlorine is added or chlorine compounds such as sodium hypochlorite is added to water. This method is used to kill certain bacteria and other microbes in tap water as chlorine is highly toxic.

Additional Information:
When handled properly according to the manufacturer's direction chlorine bleach is not only safe but it also helps keep people healthy by killing harmful germs on surfaces.
However, when chlorine bleach is misused for example mixed with ammonia or acid the results can be harmful for health.

Note: Chlorine kills pathogens such as bacteria and viruses by breaking the chemical bonds in between their molecules. Disinfectants that are used for this purpose consist of chlorine compounds, which can exchange atoms with other compounds such as enzymes in bacteria and other cells. This results in disinfection.