Water Hardness Of Salt Concentration Essay

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Introduction The key to life is water. The only known planet to have stable bodies of water to support life is Earth.1 All water however, is not pure H2O. Water often times has other compounds and chemicals mixed with it including salts. Over time plants and animals have adapted to how much salt it can consume and survive.1 These lifeforms that adapted to low salt concentrations live in freshwater habitats. Freshwater typically has a salt concentration of less than 1%.2 Although sometimes low, the salts that are most commonly found in water are formed with the cations Ca2+ and Mg2+.3 Water hardness is a measure of the concentration of calcium and/or magnesium ions in water.3 Water becomes hard as it drains through limestone, dolomite and other minerals. A high concentration of these ions results in a hard water sample, while a low concentration is soft.4 Water hardness is important in that it can cause many problems. The equation below shows how calcium can create problems.
“Calcium bicarbonate → Calcium carbonate + Water + Carbon dioxide
Ca(HCO3)2 → CaCO3 + H2O + CO2”3

Calcium carbonate, also known as scale,is sometimes referred to as “one of the banes of industry”4. The formation of scale blocks pipes and tubes4 and is the culprit behind the hated bathtub rings.3 To fix these problems, it is important to understand water hardness. Water hardness can be determined in many ways. EDTA titrations and atomic absorbance spectroscopy (AA) are the most
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