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Chemistry revision
Hard and Soft water
Question | Answer |
---|---|
What two main compounds are found in hard water? | Magnesium and Calcium. |
What is temporary hardness? | The property of hard water that can be removed by boiling the water. |
What is permanent hardness? | The property of hard water that cannot be removed by boiling the water. |
What is the problem with hard water? | Hard water wastes soap by producing scum that must be rinsed off. |
How do you 'soften' permanently hard water? | By using an ion exchange column. |
What is an ion exchange column? | A device used to soften hard water. Contains a resin with an excess of Sodium (Na+)ions. When the water passes through the column the Calcium (Ca2+) ions are exchanged for Sodium ions |
Why does ion exchange soften all types of water, while boiling on removes temporary hardness. | Because an ion exchange swaps Calcium ions with Sodium ions, meaning the Calcium ions aren't there anymore. The water is no longer hard. |