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Investigate the hardness of water in 5 different water solutions

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Chemistry coursework: Hardness of water Planning Aim To investigate the hardness of water in 5 different water solutions Background knowledge about hard water The hardness of water is caused by the presence of Calcium 2+ and magnesium 2+ ions in the water. These minerals in water can cause some everyday problems. They react with soap and produce a deposit called "soap scum" that remains on the skin and clothes and, because it is insoluble and sticky, cannot be removed by rinsing. Soap curd changes the pH of the skin and may cause infection and irritation. It also remains on the hair making it dull and difficult to manage. Soap scum picks up the dirt from laundry water and holds it on cloth, contributing to a grey appearance of white clothes. It is especially troublesome when wash water is allowed to drain through the clothes. The use of synthetic detergents may help a little, but the active ingredient in the detergent is partially inactivated by hardness and more detergent must be used for the same cleaning task. Some detergents will produce soap during the reaction with oil or grease on the surface being cleaned and as a result they will also deposit soap curd. ...read more.


The lather shall be measured using the same ruler, which will be accurate to 1mm. For the Ph, chloride, carbonate and sulphide test, the same amount of drops of the respective solution shall be used accordingly. Lather test A B C D E * 4ml of the boiled water will be placed into each test tube using a measuring cylinder * One spatula of solid soap will be placed in separate test tubes, along with distilled water to make a soap solution will be placed into the test tubes labelled A to E 1 spatula of soap solution with distilled water These test tubes are separate to the other test tubes. * We will now put 0.5ml of the newly made soap solution into the test tubes labelled A to E. The test tubes will then be shaken 5 times, again making sure this is a fair test, all the test tubes will be shook the same amount of times. 0.5ml of soap solution into the test tubes A B C D E * The height of the lather in each test tube will be measured with the ruler. The next series of tests are to clarify and back up the prediction that I have made earlier. ...read more.


of Precipitate Test 5: Testing for Sulphide Solution Colour Precipitation A No Change Light B No Change Pale C No Change None D No Change Light E No Change Pale 4 drops of Barium Chloride, shake 5 times Analysis Here I shall show the graphs for the three experiments Here is the graph for the average height in lather, for all the test tubes Conclusion In my conclusion, I conclude that Test tube C had the softest water, as the most lather was produced in that particular test tube. In relation to my background theory earlier, the softest water would produce the most lather, which is what I had concluded here. Evaluation I think generally the experiment was succesful, Test tube C seemed to have the softest water, mistakes of course wouldve caused a difference in the graphs and the statistics. In short, I produced results that was consistent to the theory of the hardness of water and prediction that I made at the start. What I could've done to improve my experiment: * Repeated the experiment more times to get greater accuracy * Used more water samples, a greater variety for more accuracy I think application of these things wouldve given a wider range of possibilties open for interpretation, the results wouldve been more reliable, as they were based on more variables. ...read more.

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