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InterviewSolution
| 1. |
(a) What is hardness? How it is determined by EDTA method? Explain. |
| Answer» <p>Water “hardness” refers to the amount calcium and magnesium dissolved in the water. The “harder” the water (the more minerals are dissolved in it) the quicker mineral deposits build-up in water pipes and tanks that it runs through, requiring more frequent maintenance. Hot water pipes and boilers are particularly susceptible to mineral build-up. This is why water is often “softened” by removing a percentage of the minerals from the water.EDTA is an acid used to dissolve “limescale,” which is a kind of mineral made primarily of calcium carbonate that often builds up over time in water pipes, tanks, etc. The EDTA method involves titrating EDTA into a sample of water. The amount of EDTA required to fully react with all of the dissolved calcium in the water can be used to determine the “hardness” of the water.</p> | |