1. Access to medicines: “Three inaccuracies” Note: The original reagent bottle can not be returned to the laboratory after it has been taken out or used. A: Access to solid medicines Use a tweezers for block solids (specific operation: first place the container horizontally, put the medicine into the mouth of the container, and then

1.Test tubes are commonly used: 2.The beaker is mainly used for: 3. Flask (round bottom flask, flat bottom flask): 4. Erlenmeyer bottles are commonly used for: 5.Evaporating dishes are usually used for concentration or evaporation of solutions. 6.The plastic dropper is used to remove and add a small amount of liquid. Note: 7.A measuring cylinder

1. How to wash pipettes and suction tubes? Both the pipette and the suction tube can be washed with tap water, then rinse with distilled oil, when it is dirty (when the inner wall is hanging with water drops), it can be washed with chromic acid washing solution. 2. What is the method of washing

1、What is the method of oiling an acid burette? Remove the piston, use a clean paper or cloth to dry the inner wall of the piston and the sleeve. Use our fingers to apply a small amount of Vaseline to apply a thin circle on both ends of the piston. Do not apply Vaseline on both

Physical and chemical testing is one of the main testing parts of laboratory testing, and its testing results are the main scientific basis for determining product quality. There are three main sources of error in physical and chemical laboratories: systematic error, random error and human error. Then, what are the specific causes of each error?

Glassware are often used during the experiment, so accidents are common, so it is very important to know the properties of the glass before using glassware.Hardness ———– hardness is 6~7, brittle, cracks are shell-like like sharp tools.Strength ———– Strong resistance to pressure but weak tensile strength , easy to break.Heat resistance ——– poor thermal conductivity,

Glass cutting 1.. It is necessary to fully confirm whether the glass to be cut is deformed or cracked, and it cannot be used if it is unqualified. 2. The glass tube (rod) must be passivated in advance if both ends is sharp. 3. First use a trowel to draw a scratch at the place

1、Round (flat) bottom Boiling flask ●Specification: Capacity (mL) 5-2000, can be matched Rubber stopper ●Main use: heating and distilling liquid, flat-bottomed flask can be equipped Washing liquid ● Note: Generally avoid direct heating on the fire, should be stone Cotton net or various heating sleeves, heating bath heating, etc., ●The contents are not More than 2/3

1. The heating process is a common step in physical and chemical analysis. In actual work, some people often ignore or simply can’t figure out which instruments can be heated, and even make mistakes. In fact, laboratory glassware are not directly heated, such as measuring cylinders, measuring cups, volumetric flasks, reagent bottles, etc. can not

1, Crystal glass is called artificial crystal. Because natural crystal is rare and not easy to mine, it can not meet people’s needs, so artificial crystal glass is born. Because of its high transparency, it can be made into a variety of handicrafts. 2, Ordinary glass Ordinary glass is a relatively transparent solid material that