Why is chlorine used to treat local water supplies? (A) To make water suitable for swimming (B) To kill micro-organisms living in the water (C) To promote sedimentation of finely suspended solids - HSC - SSCE Chemistry - Question 11 - 2001 - Paper 1

Chlorine is a potent disinfectant used in water treatment processes primarily for its ability to kill harmful microorganisms. This includes bacteria, viruses, and protozoa that can pose significant health risks if ingested through contaminated water. By adding chlorine to water supplies, it effectively reduces the risk of waterborne diseases and ensures the water is safe for public consumption. Therefore, option (B) is the correct answer.