Question
Explain: Hardness of water and its types.
Answer
The hardness of water refers to the presence of dissolved minerals, primarily calcium and magnesium ions, in the water. Here’s a brief explanation of water hardness and its types:
- Hard Water: Water that contains a high concentration of calcium and magnesium ions is considered hard water.
- Temporary Hardness: Temporary hardness is caused by the presence of bicarbonate ions (HCO3–) in water, which can be removed by boiling or through the addition of lime (calcium hydroxide).
- Permanent Hardness: Permanent hardness is caused by the presence of non-carbonate minerals, such as sulfates and chlorides of calcium and magnesium. It cannot be removed by boiling and requires other methods like ion exchange or lime softening.