[공학]칼슘의 정량

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칼슘의 정량

목차

1. Title
2. Date
3. Principle
4. Apparatus & Reagent
5. Procedure
6. Result
7. description

본문내용

3. Principle
Calcium is the most abundant, essential mineral in the human body. Of the two to three pounds of calcium contained in the average body, 99% is located in the bones and teeth. Calcium is needed to form bones and teeth and is also required for blood clotting, transmission of signals in nerve cells, and muscle contraction. The importance of calcium for preventing osteoporosis is probably its most well-known role. Although calcium plays at least some minor role in lowering blood pressure, the mechanisms involved appear complex and somewhat unclear.1 The level of calcium in the blood is tightly regulated by parathyroid hormone (PTH), and low intake of calcium causes elevations in PTH, which in turn have been implicated in the development of hypertension.2 High calcium intake has also been associated with a reduced risk of cardiovascular disease in postmenopausal women.

4. Apparatus & Reagent
1) Apparatus
Beaker
Burner
Filter paper
crucible
5. Procedure
1) weigh χg CaCl2․2H2O that containing no more than 0.2000g of [Ca2+]
2) dissolve in 200㎖ H2O add 5.0㎖ of HCl (1:1)
3) add 50㎖ ammonium oxalate solution that containing about 3.000g of (NH4)2CaO4H2O
4) add a few drops of methyl red indecator
5) heat to 70~80℃ add 1:1 NH3H2O drop by drop, stirring, color change.
6) leave alone to precipation
7) filtrate, wash 3~4times with 0.1% ammonium oxalate solution
8) dissolve in 50㎖ of hot 1:4 HCl
9) dilute to 200㎖, add about 1.000g of (NH4)2CaO4H2O dissolve in 5~10㎖ of H2O
10) repeat 4,5,6
11) burn at a low temperature
12) burn of more than 830℃

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