Water Hardness
- Created by: Niamh Bush
- Created on: 29-04-13 16:30
View mindmap
- Water Hardness
- Permanently Hard Water
- Caused by the presence of dissolved calcium sulfate
- Can be softened by adding washing soda (sodium carbonate)
- The added carbonate ions react with the calcium and magnesium ions. The calcium and magnesium ions are no longer dissolved in the water
- Can be softened by running water through 'ion exchange columns'.
- The columns have sodium (or hydrogen) ions and exchange them for the calcium and magnesium ions in the water
- Temporarily Hard Water
- Caused by the presence of hydrogen-carbonate ions
- Removed by boiling
- The hydrogen-carbonate ions decompose to form calcium carbonate which is insoluble. This is called limescale
- Can be softened by adding washing soda (sodium carbonate)
- The added carbonate ions react with the calcium and magnesium ions. The calcium and magnesium ions are no longer dissolved in the water
- Can be softened by running water through 'ion exchange columns'.
- The columns have sodium (or hydrogen) ions and exchange them for the calcium and magnesium ions in the water
- Soft Water
- Makes a lather when it reacts with soap
- Hard Water
- Makes scum when it reacts with soap unless a soapless detergent is used
- More soap needed = more money
- Calcium and magnesium ions make the water 'hard'
- The calcium and magnesium ions are dissolved from rocks (such as limestone, chalk and gypsum) as magnesium sulfate and calcium sulfate
- The scum produced is insoluble
- Forms scale when heated
- This reduces the efficiency of the appliance, therefore they will need to be regularly replaced- costing money
- The build up eventually results in the blocking of pipes
- Acts as a thermal insulator so a kettle (for example)would take longer to boil
- Calcium ions are good for healthy teeth and bones. People drinking hard water are less at risk of developing heart disease
- Makes scum when it reacts with soap unless a soapless detergent is used
- Permanently Hard Water
Comments
No comments have yet been made