Basic knowledge of titration analysis nbsp Nanjing

Basic knowledge of titration analysis nbsp; Nanjing qunfa Analytical Instrument Co., Ltd.

basic knowledge of titration analysis the rapid development of science and technology of plastic film prototype

1. The burette should be washed with potassium dichromate sulfate lotion, washed with tap water, and then washed with distilled water for more than 3 times, based on the principle of no water droplets hanging on the inner wall. Wash with titration standard solution for 3 times before use. (when the buret is washed and used immediately and is not controlled dry, the washing times of standard solution should be increased)

2. Take out the glass piston at the lower end of the acid burette after cleaning, wipe it dry with filter paper, wash it with a layer of Vaseline, (be careful not to block the small hole), and then put on a rubber band. At this time, the glass piston should rotate flexibly. The glass beads at the lower end of the basic burette should be of appropriate size and easy to operate

3. No matter what type of burette is injected into the solution, there shall be no bubbles. The acid burette is transparent and easy to operate. It can directly discharge bubbles. Use your fingers to squeeze the glass ball at the lower end of the basic burette, and then bend the hose upward to make the solution flow out and bring out the bubbles

4. The titration speed should be 3-5 titration per second. After titration to the end point, wait for more than 30 seconds before reading. One way to read is to clamp it on the titration rack. With this method, the buret should be vertical on the titration rack (both sides of the buret should be vertical when viewed from the front and side). The other is to hold the buret for reading. When reading with this method, hold the upper end of the buret and make it vertical. When reading, the line of sight should be level with the liquid level. First look at the large scale, and then read the sub scale. It is best to read it twice, and make the original record

5. Principle of reading: if the solution in the burette is colorless, read the tangent of the lower edge of the meniscus of the solution. If it is not clear, put a piece of white paper with blue or black lines behind the buret and read the number of the intersection of the two tips. If it is a dark solution, the plane above the readable solution or the highest point on both sides where the liquid level contacts the guest wall. (the reading method should always be consistent)

6. If the titration operation is carried out in the triangular flask, the left hand operates the burette piston, the right thumb and index finger hold the upper end of the triangular flask, and the whole bottle holding hand should be lifted up, so that the triangular flask is not covered by the hand, which will affect the observation. 3.5.3 for non ferromagnetic materials such as silver, cadmium, chromium, aluminum, magnesium, titanium, zinc, etc., if the titration is carried out in the beaker, hold the glass rod in your right hand, and the glass rod should be 1/3 or cm higher than the beaker

7. When titrating, the burette should stretch into the mouth of the bottle (cup) for about 1/3-1/4 or 1cm. The left hand should control the titration speed, and the right hand should constantly shake the conical bottle evenly to make the solution fill Alibaba, the world's largest e-commerce platform, and its rookie logistics network reaction. When shaking, do not collide with the buret. The upper end of the conical flask (i.e. the hand-held part) cannot deviate from the central axis (the tip of the buret). Only the lower end (bottom) of the conical flask can be shaken, generally clockwise. If titrating with a beaker, the burette should be 1-2cm away from the beaker wall when extending into the beaker. Hold the glass rod in your right hand and stir it fully. The glass rod cannot collide with the beaker wall

8. During each titration, the initial reading of the solution should preferably start from "0". If the titration consumes little solution, the initial reading can also start from the next integer, such as 10.00ml, 20.00ml, etc. If you titrate half a drop of solution, you can use a washing bottle to blow it down, or gently lean the tip of the burette against the inner wall of the conical flask, and you can also use a glass rod to guide it down. Titration should be carried out in a room with sufficient light, and it is best to put white tiles on the titration table

9. When filling the buret with titration solution, it is best to pour directly into the buret from the reagent bottle; If conditions do not permit, it needs to be transferred with a beaker, which should be washed with titrant for more than 3 times, with the name and concentration of the solution written on it and covered with a watch glass

10. After titration, the remaining titrant shall not be poured back into the original solution (mother liquor). Rinse the burette and put it upside down on the titration rack

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