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Notes on Dialysis testing.

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Dialysis Materials: starch glucose sodium chloride iodine solution silver nitrate solution Benedict's solution Equipments: dialysing tubing glass rod cotton thread beaker dropping pipette test tubes test tube rack test tube holder Bunsen burner tripod gauze matches stop clock Method: 1. Wet the piece of dialysing tubing and open it using a glass rod. Tie a secure knot in one end of the tubing. 2. Inject the mixture of starch, glucose and sodium chloride solution into the open end of the dialysing tubing using a dropping pipette. 3. When the tubing is nearly full tie a thread of cotton tightly round the open end of the dialysing tubing. Wash the tubing throughly under the tap and then wash it again using distilled water. 4. Suspend the dialysing tubing in a beaker and fill it with distilled water up to the level of knot. ...read more.


Positive result: white colour Starch: add a few drops of iodine solution to the sample. Positive result: dark violet colour The tested samples Time (min) 0 TEST 1 5 TEST 2 Glucose light blue transparent carrot Chloride blue transparent white Starch brownish orange brownish orange 10 TEST 3 15 TEST 4 20 TEST 5 carrot yellow brown white white white brownish orange brownish orange brownish orange 25 TEST 6 25 (inside the dialysing tubing) TEST 7 carrot carrot white white brownish orange dark violet Chloride from TEST 2 to TEST 6 gradually became less and less transparent. Conclusion and evaluation: The word 'dialysis' originates from a greek word, and it means separation. In this experiment different compounds were separated according to their size with the help of a dialysing tubing. ...read more.


Chloride could get through the tubing as well as glucose. But unlike glucose, chloride from TEST 2 to TEST 6 showed less and less transparency, as a result of gradual quantity change. Not all the chloride particles oozed out of the tubing since TEST 7 resulted a white liquid. Starch, being the largest of the 3 tested compounds, could not get through the tubing; TEST 2, 3, 4, 5 and 6 had the same results as TEST 1 had. TEST 7, resulting in dark violet colour testified it. Dialysis has huge practical applications. The largest is in human health care. If someone has a kidney failure, urea will begin to accumulate in the blood. It can be removed by connecting the patient to a dialysis machine. Blood then circulates through the membrane and the urea (being a small molecule) is removed. Dialysis of blood is the biological function of kidney, that is why this organ is vital. 1 ...read more.

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