Question

The gas used as a disinfectant for sterilizing drinking water is -

• A. oxygen.
• B. chlorine.
• C. fluorine.
• D. nitrogen.

Answer 1

The correct option is B

chlorine.

The explanation for the correct option -

• All the given elements are non-metals.
• Non-metals are those chemical elements that in reaction with metals (positively charged ions) gain electrons. For example - Hydrogen$\left({\mathrm{H}}_2\right)$, Oxygen$\left({\mathrm{O}}_2\right)$, etc.
• Chlorine is a toxic gas with a greenish-yellow color.
• It has germicidal properties due to which it is used to sterilize drinking water and swimming pool water.
• Water chlorination is the process of adding chlorine. This method is used to kill certain bacteria and other microbes in tap water.

The explanation for the incorrect options -

• Option A is incorrect because Oxygen gas plays a vital role in respiration and combustion processes.
• Option C is incorrect because Fluorine is a yellow-colored gas having a suffocating odor. It is used in the production of fluorocarbons.
• Option D is incorrect because Nitrogen has its major use in the production of Ammonia by Haber's process, fertilizers, insecticides, etc.

Hence, option B is the correct answer.