Hardness in Water

Hardness in Water

• Water hardness is primarily due to the presence of calcium and magnesium ions.
• There are two types of hardness: temporary hardness and permanent hardness.
• Temporary hardness is caused by hydrogencarbonate ions (HCO3-) which can be removed by boiling.
• Boiling precipitates the calcium and magnesium ions, effectively ‘softening’ the water.
• Permanent hardness is due to sulphate or chloride ions (SO42- or Cl-). This cannot be removed by boiling and is instead treated using water softeners.
• The main water softening methods are Ion exchange and precipitation methods.
• Ion exchange involves swapping calcium and magnesium ions in the water for sodium ions, using a resin.
• Precipitation involves adding washing soda (sodium carbonate) to water. This reacts with the calcium or magnesium ions forming a precipitate.
• Using hard water can cause scaling in pipes and appliances, affecting their efficiency.
• Scaling is the term used for the build-up of solid deposits in pipes and appliances.
• However, drinking hard water has health benefits as the needed amount of calcium and magnesium for the human body can be partially provided.

Markdown is as follows:

**Hardness in Water**
- Water hardness is primarily due to the presence of **calcium** and **magnesium** ions.
- There are two types of hardness: **temporary hardness** and **permanent hardness**.
- Temporary hardness is caused by **hydrogencarbonate ions (HCO3-)** which can be removed by boiling.
- Boiling precipitates the calcium and magnesium ions, effectively 'softening' the water.
- Permanent hardness is due to **sulphate** or **chloride ions (SO42- or Cl-)**. This cannot be removed by boiling and is instead treated using water softeners.
- The main water softening methods are **Ion exchange** and **precipitation** methods.
- **Ion exchange** involves swapping calcium and magnesium ions in the water for sodium ions, using a resin.
- **Precipitation** involves adding washing soda (sodium carbonate) to water. This reacts with the calcium or magnesium ions forming a precipitate.
- Using hard water can cause scaling in pipes and appliances, affecting their efficiency.
- Scaling is the term used for the build-up of solid deposits in pipes and appliances.
- However, drinking hard water has health benefits as the needed amount of calcium and magnesium for the human body can be partially provided.