The most contacted and used glass instruments in the laboratory is the most, if the correct cleaning and maintenance of glass instruments?

　　(1) After washing the glass instruments upside down when the wall should not hang water beads, and then use a small amount of distilled water or deionized water to shabu-shabu several times.

　　(2) glass instruments to pay attention to the use of a variety of different nature of the washing solution, be sure to remove the previous washing solution before using the next washing solution to avoid mutual influence.

　　(3) the measurement of standard substances or samples of glass instruments can not be used to dry at high temperatures, should be inverted to dry.

　　Here we learn about the use of common laboratory glassware and the use of specifications:

　　Beakers to prepare solutions, dissolve samples, etc.; heating should be placed on asbestos nets, so that they are heated evenly, and generally not burned dry.

　　Conical flask heating processing samples and volume analysis titration; in addition to the same requirements as above, grinding mouth conical flask heating to open the plug, non-standard grinding mouth to maintain the original matching plug .

　　Round (flat) bottom flask heating and distillation of liquids; generally avoid direct fire heating, separated by asbestos nets or a variety of heating bath heating.

　　Round bottom distillation flask distillation; can also be used for a small amount of gas generation reactor, the same precautions as the round bottom flask.

　　Kjeldahl flask for decomposition of organic substances Place the flask on an asbestos net for heating, and do not orient the mouth of the flask towards yourself and others.

　　Wash the flask with purified water or wash the precipitate with washing solution.

　　Measuring cylinders and measuring cups are used to roughly measure a certain volume of liquid; they cannot be heated, cannot be used to prepare solutions in them, cannot be baked in an oven, and should be added or poured out along the wall during operation.

　　Volume bottle to prepare the exact volume of the standard solution or the measured solution; non-standard grinding mouth plug to maintain the original match; leaky can not be used; can not be baked in the oven, can not be heated with direct fire, can be heated in a water bath.

　　Burette (25 50 100ml) volume analysis titration operation; divided into acid type, alkali type piston to the original; leaky can not be used; can not be heated; can not be long-term storage of lye; alkali type tube can not be put with the rubber role of the titration solution.

　　Micro buret (1 2 3 4 5 10ml) micro or semi-micro analytical titration operation Only piston type; the rest of the precautions as the standard buret.

　　Pipette accurately removes a certain amount of liquid; cannot be heated; upper end and tip must not be knocked; graduated pipette; accurately removes various amounts of liquid.

　　Weighing bottle short shape used to determine the dry weight loss or drying benchmark in the oven; high shape used for weighing benchmark, samples can not be covered tightly grinding mouth plug baking, grinding mouth plug to the original match.

　　Reagent bottle: fine mouth bottle, wide mouth bottle, under the mouth bottle fine mouth bottle for storage of liquid reagents; wide mouth bottle for solid reagents; brown bottle for storage of light easily decomposed reagents can not be heated; can not be prepared in the bottle in the process of operation of a large amount of heat released solution; grinding stopper to maintain the original match; put the bottle of alkali solution should use a rubber stopper, so as not to open over time.

　　Dropper bottle for reagents to be added drop by drop The main matters are the same as reagent bottles.

　　The long-necked funnel is used for quantitative analysis and filtration of precipitation; the short-necked funnel is used for general filtration.

　　Drip funnel: drops spherical pear-shaped cartridge separation of two immiscible liquids; for extraction separation and enrichment (mostly pear-shaped); preparation of reactions with liquid (mostly spherical and drops funnel) grinding mouth cork must be original, leaky funnel can not be used.

　　Test tubes: ordinary test tubes, centrifugal test tubes Qualitative analysis of test ions; centrifugal test tubes can be used in a centrifuge to separate solutions and precipitates by centrifugal action; hard glass test tubes can be heated directly on the flame, but can not gather cold; centrifugal tubes can only be heated in a water bath.

　　(Na) colorimetric tube colorimetric, turbidimetric analysis; not direct fire heating; non-standard grinding mouth plug must be original; attention to maintain the transparency of the tube wall, not with decontamination powder brush.

　　Condensation tube: straight spherical serpentine air condensation tube for cooling distilled liquid, serpentine tube for condensing low boiling point liquid vapor, air condensation tube for condensing boiling point of 150 ℃ or more liquid vapor can not be aggregated cold aggregated heat; note that from the lower mouth into the cooling water, the upper mouth out of water.

　　Filter flask to receive filtrate when pumping It is a thick-walled container and can withstand negative pressure; it cannot be heated.

　　Surface dish cover beakers and funnels, etc. can not be heated by direct fire, the diameter should be slightly larger than the covered container.

　　Grinding bowl to grind solid reagents and samples, etc.; can not grind substances with the role of glass can not be hit; can not be baked.

　　Dryer to keep the dried or burned material dry; can also dry a small amount of prepared products Bottom put discolored silica gel or other desiccant, cover the mouth of the grinding coated with an appropriate amount of petroleum jelly; not red hot objects into, into the hot objects to open the lid from time to time to avoid the lid jumping up or cooling can not open the lid.