C3, Hard and soft water 0.0 / 5 ? ChemistryWater hardness and solubilityGCSEAQA Created by: emmajane_Created on: 12-04-14 11:13 What determines if water is hard or soft? The amount of mineral ions dissolved in the water 1 of 15 What type of mineral ions does hard water contain? What do they form? Dissolved compounds such as magnesium and calcium and they form scum 2 of 15 What does soft water form that hard water doesn't? Forms lather from soap 3 of 15 What do you ahve to perform to find out if water is hard or soft? Titrations 4 of 15 Name step one of titration Put a known volume of water in a conical flask 5 of 15 Name step two of titration Add soap solution with a burette 6 of 15 Name steps three and four of titration 3. Mixture swirled to form a lather 4. Harder the water- the more soap solution needed 7 of 15 How can yoif water is temporarily hard and what does it contain? It softenes at boiling point and contains hydrogen carbonate ions. These decompose at boiling point 8 of 15 How can you tell if water is permenantly hard and which ions does it contain? Stays hard at boiling point and contains sulphate ions that don't decompose at boiling point 9 of 15 Name 3 benefits of hard water 1. Tastes better 2. Helps reduce heart disease 3. Good for bones and teeth 10 of 15 Name 2 dissadvantages of hard water 1. More soap needed to produce lather- higher coss 2. Scum produce which looks bad 11 of 15 Name a drawback of temporary hard water Reduces efficiency of appliances because it creates limescale blocking pipes 12 of 15 How do you soften hard water? Remove sodium ions 13 of 15 How do you remove sodium ions from water? Using exchange columns 14 of 15 Why does adding sodium carbonate (washing powder) to hard water soften it? Thr carbonate ions react with calcium and magnesium ions, producing an insoluble precipitate. This produces limescale 15 of 15
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