Question

Water is often treated with chlorine to:
A.Cause sedimentation
B.Remove insoluble impurities
C.Increase oxygen content
D.Kill germs

Answer 1

Hint:To answer this question, we need to explore the properties of chlorine. Chlorine has various uses as a disinfectant.

Complete step by step answer:
The reason for treating chlorine with water is due to the disinfectant properties of chlorine. To protect drinking water from various pathogens (disease causing organisms), water is often treated with disinfectants before its supply. Chlorine is most commonly used for this purpose.The process of adding chlorine or chlorine compounds like sodium hypochlorite to treat water is known as water chlorination. This process is used to kill various bacteria, viruses and other microorganisms present in the supply water since chlorine is highly toxic. It helps to prevent the spread of waterborne diseases like dysentery, typhoid and cholera.

Hence, the correct option is option D.

Additional information: Since chlorine is a strong oxidizing agent, it causes the oxidation of organic molecules. Chlorine gas does not carry a charge and thus can easily enter through the negatively charged surface of pathogens. It then disintegrates the lipids composing the cell wall and also reacts with intracellular proteins and enzymes. The enzymes and proteins in the cell become nonfunctional causing either the death of the microbes or ceasing their multiplication.

Note:
The use of chlorine can be hazardous in some cases. Chlorine may react with organic compounds naturally present in water supply forming disinfectant by-products like haloforms and haloacetic acids.
Bromoform and dibromo chloroform cause various health hazards. Bromoform if exposed in high doses, slows down brain activity causing sleepiness or sedation. Long term exposure can cause liver and kidney cancer, unconsciousness and heart diseases.