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    Hey everyone, could someone please explain hard and soft water, what scale is and how to get rid of it please, thank you! Knowing my luck, it's going to be the six marker in the exam!
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    So hard water is when calcium and magnesium ions are dissolved in the water. You can either have temporary hard water or permanent hard water:
    - Temporary hardness is caused by hydrogencarbonate ions (so calcium hydrogencarbonate ions in water would make it temporary hard water)
    - Permanent hardness is caused by sulfate ions (e.g. calcium sulfate ions dissolved in the water would make it permanent hard water)

    Scale is formed when you heat hard water and it consists of mostly calcium carbonate. The problems with it is that it blocks pipes,boilers and kettles and makes them less efficient. Scale is a thermal insulator as well so if it is on a kettle, it means the water takes longer to boil so again reduces efficiency.

    Not really sure how you get red of scale, do you mean how do you get rid of the hard water?

    Also if anyone has anything else to add that would be great because this is my worst topic too!
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    Hey

    With hard water, when you mix it with soap, it forms unsightly scum, whereas with soft water, a lather will be formed. This scum is caused by dissolved magnesium and calcium ions reacting with the water.

    There are 2 types of hard water: permanently hard and temporarily hard. Temporary hardness is caused by the ion HCO3-. This can be easily removed- all you do is boil the water and it will no longer be hard water. This means that scum will no longer be formed when you mix soap with the water.

    Permanent hardness is removed by two ways: adding sodium carbonate or running the water though an ion exchange column.

    The sodium carbonate works because the CO3 2- ion reacts with the Ca 2+ or the Mg 2+ ions, causing an insoluble precipitate to be formed. The water is no longer hard as the Ca 2+ and Mg 2+ ions are removed.

    The ion exchange column works by substituting the Ca 2+ and Mg 2+ ions with the 2H+ or 2Na+ ions in the exchange column. Although the Ca and Mg ions are removed, they will have been substituted with the H or Na ions. The water is no longer hard as the Ca and Mg ions are removed.

    The scale is the insoluble precipitate formed when temporarily hard water is heated. The hot water in the pipes cause CaCO3 to precipitate out of the water, and this precipitate is the scale. I'm not quite sure on how to remove it, but you could prevent it- perhaps by heating the water before it is transported through the pipes, so that the CaC03 will have already precipitated out.

    Although you may want soft water as the limescale caused will block pipes and reduce their efficiency, hard water is better for you- the Ca 2+ ions are good for our teeth and bones. The Na ions that you could use to remove the hardness can increase risk for heart problems (related to why people say salt (NaCl) is bad for you- it causes high blood pressure).

    Hope this helps
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    Thank you guys! Helped a lot! Good luck in your exams!
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    Thanks guys! It was the six mark question in the c3 exam!
 
 
 
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