Operation and use of commonly used glass instruments for burettes

1. Operation:

Operation of the acid burette: control the piston with the left hand, bend the ring finger and the little finger in the palm, gently press against the outlet tube, the thumb is in front, the index finger and middle finger are behind, the fingers are slightly bent, and the piston is gently buckled inward, and the palm is empty. To prevent ejection of the piston, resulting in leakage.

Alkaline burette operation: the thumb of the left hand is in front and the index finger is behind, pinch the place where the glass beads are located in the rubber tube slightly above, and squeeze the rubber tube to the right to form a gap between it and the glass beads, so as to release the solution. Be careful not to pinch the rubber tube under the glass beads, so as to avoid air entering and forming air bubbles when you let go.

It is best to start each titration with a reading of 0.00.
There should be no suspension at the tip of the outlet pipe during titration. The lower end of the burette extends into the mouth of the bottle for about 1cm during titration.

2. Reading:

The burette can be clamped on the titration rack or removed from the pipe rack, and the upper part of the burette can be held by hand without scale. Both methods need to keep the tube vertical.

The same reading method should be used for reading and final reading.

Colorless solution: The line of sight is at the same level as the lowest point of the meniscus of the solution.

Colored solutions: Read the highest points on both sides of the liquid level.