Natural water is said to be hard when it contains metal ions such as Ca 2+ and
Question:
Natural water is said to be “hard” when it contains metal ions such as Ca2+ and Mg2+ that interfere with the use of detergents. These ions are often present in natural water as the soluble hydrogen carbonates, Ca(HCO3)2 and Mg(HCO3)2. One way to remove these ions from natural water is to add lime, Ca(OH)2, to it. This addition of a calcium compound may seem paradoxical. What happens to a solution of calcium hydrogen carbonate when the pH is raised? Does this solve the paradox? Explain.
Step by Step Answer:
The molecular and net ionic equations for the reaction between an aqueous solution of ...View the full answer
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The experiment aims to show the impact of various beverages on teeth by using eggs as a representation of enamel. Three eggs are boiled and then placed in glasses filled with fizzy drinks, vinegar, and mango juice for 24 hours. The shells of eggs are similar to enamel as they are composed of calcium carbonate, and enamel is primarily made of calcium phosphate. The eggs are then observed to demonstrate the effects of the different liquids on teeth and the importance of brushing regularly. The egg placed in fizzy drink has turned dark in color but can be cleaned by brushing with toothpaste and rinsing with water. The egg placed in vinegar has had its shell softened due to the chemical reaction of vinegar and calcium carbonate, which can\'t be reversed. This highlights the fact that acids are more damaging to teeth than other substances. The egg placed in mango juice represents the process of bacteria in the mouth converting sugars and starches into acids that form plaque, which can be prevented by brushing. The use of fluoride in toothpaste is also highlighted as it slows down the demineralization process and protects the enamel. The importance of brushing teeth twice a day is emphasized.
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