Red Seal Plumbing Practice Exam

What is the principle of water operation in softening?

1. Chlorination

2. Filtration

3. Sodium cycle ion exchange

4. Reverse osmosis

The correct answer is: Sodium cycle ion exchange

Sodium cycle ion exchange is the principle of water operation in softening. This method uses salt, specifically sodium chloride or potassium chloride, to replace the calcium and magnesium ions in hard water with sodium ions. This process removes the minerals that cause water to be hard, resulting in softened water. Chlorination is the process of adding chlorine to water to disinfect it and make it safe for consumption. Filtration involves passing water through a physical barrier to remove particles and impurities. Reverse osmosis is a process that uses a semipermeable membrane to remove dissolved solids, ions, and larger particles from water. While these methods may also be used in water treatment, they are not the principle of water operation in softening.