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Common experimental instruments and their use
I. Classification of common instruments
Generally, according to the main use of the instrument, the common chemical experimental instruments can be divided into the following 8 categories:
(i) Measurement category
Instrument for measuring quality, volume, temperature, density, etc. Many of these instruments are glass gauges. Mainly have burette, liquid tube, cylinder, measuring cups and so on.
(ii) Reaction classes
The instrument used for chemical reactions also includes a part of the heating apparatus. Many of these instruments are glass or porcelain burners. The main test tube, flask, pan, crucible and so on.
(iii) Container class
Used for dressing or storage of solid, liquid, gas and other chemical reagents, such as reagent bottles.
(iv) Separation of classes
Used for filtration, separation, extraction, evaporation, burning, crystallization, fractionation and other purification operations of the instrument. Mainly funnel, liquid funnel, pan, flask, condenser, crucible, beaker and so on.
(v) Solid holding class
Supplies or instruments for fixing and holding various instruments. There are mainly iron clips, iron rings, iron racks, funnel racks and so on.
(vi) Heating class
A product or apparatus used for heating. The main test tube, beaker, flask, pan, crucible and so on.
(vii) Supporting categories
A glass tube, a glass valve, a rubber hose, a rubber stopper, etc. for assembling or connecting an instrument.
(eight) other categories
The inconvenience of belonging to any of the other instruments or supplies mentioned above.
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II. Name and use of common chemical instruments
(i) Measuring instruments
1. Measuring cups
The measuring cup belongs to the volume (symbol Ex) measure, which is used for measuring the volume of liquid discharged from the tank. The volume of the discharged liquid is the volume of the liquid being read from the scale value in the tank.
The measuring cup has 2 kinds of types. In the face of the scale table, measuring cup pour nozzle to the right, convenient left-hand operation, known as Zoo-type measuring cup. Pour the liquid mouth to the left, is called the right practice measuring cup. $number ml within the measuring cups are Zoo type, the more than ML, it belongs to the right.
2. Thermometer
A thermometer is an instrument for measuring temperature. There are many kinds of digital thermometer, heat-sensitive thermometer hemorrhoids. And the laboratory is commonly used for glass liquid temperature.
Thermometers can be divided into standard thermometers and practical thermometers in 2 categories according to their use and accuracy of measurement. The standard temperature juice has high precision, it is mainly used for correcting other thermometers. The practical thermometer refers to the thermometer used for the actual temperature measurement, the main test thermometer, industrial thermometer, meteorological thermometer, medical thermometer and so on. High-school bar-type industrial temperature juice. The range of the alcohol thermometer is 100 Shan, and the mercury thermometer uses 200 Shan and 360 range specifications.
Usage considerations
(1) A thermometer suitable for measuring range should be chosen. The use of thermometers is strictly prohibited.
(2) When measuring the liquid temperature, the liquid bubble of the thermometer should be immersed in the liquid completely, but must not contact the vessel wall, the liquid bubble should be above the liquid level when measuring the steam temperature, the liquid bubble should be slightly lower than the distillation Flask branch tube When the distillate temperature is measured.
(3) at the time of reading, the line of sight should be the highest (mercury thermometer) or lowest (alcohol thermometer) level in the meniscus of the liquid column.
(4) It is forbidden to use the temperature juice instead of the glass stick for stirring. After use should wipe clean, put in the paper sleeve, away from the heat storage.
3. Pallet Balance
The pallet balance is a kind of instrument used to weigh the mass of the material, and each balance is equipped with a box of code.
$number g (Sense of 0.1 g) and g (sense of 0.2 g) in the laboratory. Load is also called carrying volume, is to be able to weigh the maximum. The sense is the balance of the error (±), such as the sense of 0.1 g of the pallet balance, indicating that its error is Biong. 1 g, so it can not be used to weigh the quality of less than 0.1 g of the goods.
Usage considerations
(1) Weighing the balance should be placed in a smooth, and the travel code left to the scale 0, check the balance of the swing is balanced. If the balance is reached, the number of the left and right sides of the ruler indicated by the pointer swinging is nearly equal. When the pointer is stationary, it refers to the center of the ruler. If the swing of the balance is not balanced, the left and right screws can be adjusted to make the swing balance.
(2) Weighing material can not be placed directly on the tray, should be on 2 pallets on the same size of the same paper, and then the weighing reagent on paper weighing. Damp or corrosive reagents must be weighed in a glass container (e.g., a surface dish, a beaker, or a weighing bottle).
(3) Put the weighing on the left disk, weight on the right side, the code to use tweezers in the clip. First add the weight of mass, and then add the weight of the small, the last can move the code until the pointer swing to balance.
(4) After weighing, the weights should be put back into the weight box in turn. Move your code back to 0.
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(ii) Reaction instrument
1. Test Tube
A test tube is a reaction vessel used as a small amount of reagent and can also be used to collect a small amount of gas. The test tube is often divided into the flat mouth test tube, the turn mouth test tube and the branch tube. The flat mouth test tube is suitable for the general chemical reaction, the turn mouth test tube is suitable to add the rubber plug, the branch tube can be used as the gas generator, also may make the washing gas bottle or the small distillation use.
The size of the test tube is generally defined by the product of the tube diameter and tube length, commonly used for 10 X L00 mm, 12 X L00 mm, 15 X L50 mm, 18 X 180 mm, 20 X 200mm and 32 X 200 mm, etc.
Usage considerations
(1) When using the test tube, the suitable size should be chosen according to different dosage. Use a bare-handed test tube to apply Sam, food, and middle three fingers to hold the tube along. The wrist arm does not move when oscillating.
(2) The liquid is heated, should not exceed the volume, and with the desktop into a 45 "angle, pipe mouth not to yourself or others." To keep the boiling shape, it can be heated near the liquid surface.
(3) The powder-like reagent, to be used in the paper trough into the bottom of the tube, in a granular solid, should be inclined to the test tube, so that granular material along the tube wall slowly sliding into the pipe bottom.
(4) The clamping tube should be in the distance of the nozzle. When heated, the outside of the test tube should be dried and the water should not be heated. After heating, be careful to avoid sudden cold to prevent burst.
(5) When heating solid reagents, the tube bottom should be slightly above the pipe mouth, when finished, should continue to be fixed or placed on the asbestos net, let its natural cooling.
2. Beaker
A beaker is usually used as a reaction vessel for a relatively long amount of reactants. In addition, it is also used to prepare solutions, accelerate the dissolution of substances and promote the evaporation of solvents. The type and specification of Beaker are more, the low type beaker commonly used in middle school. In order to facilitate the use of a certain amount of liquid, in some beaker on the outside of the wall printed with white volume markings, this beaker is called Inper Beaker, and some call it scale beaker. Its degree is not very accurate, allowing error generally in the Shing, so on the scale table printed with "Approx", it means "approximate volume", therefore, can not be used as a measure. Beaker specifications to the size of the volume, commonly used for the $number ml, $number ml, such as a variety of ml.
Usage considerations
(1) The Beaker of the solution should not be too much, about volume, but in heating, the solution can not exceed the volume.
(2) Beaker can not be burned, in the case of a liquid can be heated for a long time, but must be padded with asbestos nets.
(3) When you take the beaker, you should take the outer wall and don't touch the inner wall. Take the beaker that is heated and use a beaker clip.
(4) When a glass rod is stirred in a beaker, the glass rod shall be uniformly screwed along the cup wall, not hitting the cup wall and the bottom of the cup.
(5) The Beaker is not suitable for long-term storage of chemical reagents, should be washed immediately after use, dry, inverted storage.
3. Flask
A flask is a container for reacting with liquids that are used as reactants and are heated over a longer period of time. The bottleneck is small, with the plug and the required accessories, is often used to occur steam or gas generator. Flask is widely used, so there are a variety of types, high school commonly used round bottom flask 2 kinds of bottom flask.
A round bottom flask is generally used as a reaction vessel under heating conditions. The flat-bottomed flask is used for gas generators under unheated conditions and is often used to assemble washing bottles. Because the bottom plane of the flat bottom flask is small, its edge is ribbed, so the stress is larger and it is easy to burst when heating. So it is generally not used in heating conditions of the reaction vessel.
The specification of the flask is differentiated by volume size and is commonly used for several types of ml, $number ml and ml.
Usage considerations
(1) The bottom thickness of the round bottom flask is more uniform and no ribs appear, which can be used for long time strong heat.
(2) When heated, the flask should be placed on the asbestos net and cannot be heated directly by flame.
(3) After the experiment, the heat source should be removed, after the cooling, the waste liquid treatment, washing.
4, distillation flask
The distillation flask belongs to the Flask class, the different person, lies in the bottleneck area has a slightly downward branch tube, it specially makes the distillation liquid the container.
Distillation flask has 2 kinds of pressure and pressure. The normal pressure steam-garnet flask also branches in the bottleneck, the middle and the lower 3 species, distillation of the higher boiling point of the liquid, the choice of branch tube in the bottleneck of the distillation flask, lower boiling point with the branch tube on both the distillation flask. And the branch tube is located in the bottleneck, commonly used to distill the general boiling point of liquid.
The specifications of the distillation flask are different in volume size and are commonly used for 2 kinds of ml and $number ml.
Usage considerations
(1) Configure accessories (such as thermometers, etc.), should choose the appropriate rubber plug, in particular to pay attention to check the tightness of the good.
(2) Heating should be placed on the asbestos net, so that it is evenly heated.
5. Conical Bottle
The cone-shaped bottle is also called a conical flask or a triangular flask.
Cone bottle body principal, the bottom big and mouth small, after the solution, the center of gravity, very convenient for hand-held oscillation, it is often used in capacity analysis as a titration container. Laboratories also use it to assemble gas generators or wash bottles.
The size of the cone-shaped bottle is divided by the volume, commonly used as 150m1, 250ml and so on.
Usage considerations
(1) Oscillation, with the right hand thumb, index finger, middle finger hold the bottleneck, the ring finger light support the lower part of the bottleneck, wrist relaxation, hand-driven fingers force, as a circular vibration.
(2) When the conical bottle needs oscillation, the solution in the bottle does not exceed the volume.
(3) If you need to heat the liquid in a conical bottle, you must pad the asbestos net.
6. Curved Neck Bottle
Curved neck bottle is also called a curved neck, it is a long history, practical and simple instrument, in addition to the only one has a grinding glass beyond the hole, container and curved neck connected, smooth lines, one. It is used as a reaction vessel or a distillation.
The biggest advantage of the curved neck bottle is the simple structure, which can be connected with the glass container through the receiver, or directly connected with the oblique flask, which does not require a rubber stopper or a rubber hose, so it is corrosion resistant. For example: In the laboratory to make nitric acid, can be from Seikou first into the solid sodium nitrate, and then add the appropriate concentrated sulfuric acid, plug the cork, micro-heat, steamed nitric acid vapor directly from the neck into the receiver, at the same time condensation into liquid. It is not due to the connection of rubber products and corrosion of nitric acid aging caused by leakage accident.
The size of the curved neck is different in volume, commonly used as $number ml, $number ml and several ml.
Usage considerations
(1) If the need to be fixed on the platform, should make its cork at the top, the iron clip to hold the curved neck near the container, so that the curved neck natural and table into an angle.
(2) The asbestos net must be padded when heating.
(3) After the experiment, it must be fixed, after cooling, the residue from the mouth of the curved neck, and then water from the cork mouth, repeatedly washed down, washed, placed.
7. Qipp Generator
The Qipp generator, often called a gas generator, was named after the invention of the Dutch chemist Qipp in 1862, which was used as a device for producing insoluble gases without heating and reacting by massive solids and liquids.
The Qipp generator consists of the upper spherical funnel, the lower container and the 3 part of the guide pipe with a piston connected with the container with a single pore rubber plug. If the acid content is larger, in order to prevent the acid liquid from the spherical funnel overflow, can be in the spherical funnel through a single hole plug to connect a safe funnel (if the amount of acid is not added, you can not add the safety funnel). Qipp generator is very convenient to use, when the piston of the trachea is punched, the liquid in the spherical funnel falls into the container and the solid contact with the narrow mouth produces the gas; when the piston is closed, the resulting gas presses the liquid into the spherical funnel, and the reaction of the solid and liquid reagents is suspended, which can be reused for a long time.
The specification of the Qipp generator is different from the volumetric size of the spherical funnel, which is commonly used as $number ml or ml.
Usage considerations
(1) When assembling the starter generator, a small amount of Vaseline should be applied between the ball-type funnel and the abrasive mouth of the container to prevent air leakage. A rubber ring or a cushion of glass wool is added to the narrow port of the middle of the container to prevent the lower part of the solid falling container, causing an accident.
(2) Check the tightness before use.
(3) When adding reagents, lump solids are added first. Select the proper size of the bulk solid reagent from the upper vent of the container into, in the vicinity of the spherical funnel neck, plug the plunger with a single hole in the trachea, open the piston, then add the liquid as reagent from the spherical funnel mouth until the container is immersed in the solid reagent, and the piston on the guide tube is closed.
(4) Qipp generators are prohibited from heating.
(5) If you need to replace liquid reagent, the generator can be placed at the experimental table, so that the bottom of the container plug out of the edge of the table, below with a volume larger than the spherical funnel container, and then carefully open the plug, be sure to make the liquid flow into the container, to be fast when the liquid, can tilt the instrument to make all the liquid poured out, plug tight plug, the square can be added liquid.
(6) Qipp generator is often used to make hydrogen, carbon dioxide, hydrogen sulfide gas. Can not be used to obtain acetylene and nitrogen oxides and other gases.
8. Crucible
The crucible belongs to the porcelain chemical instrument, which is used to burn and precipitate in the analytical experiment. Secondary schools are also used to burn crystalline hydrates, to melt salts that do not corrode porcelain, and to burn certain organics.
Ceramic crucible used for quantitative analysis of the experiment, often need to weigh, for the convenience of the Crucible often annotated its quality. Before the quantitative analysis of the burning Experiment, the blank experiment of burning weightlessness should be done, if the weightlessness exceeds the tolerance of the experiment, the vortex cannot be used.
The specification of the Crucible is different from the size of the volume.
Usage considerations
(1) In the quantitative experiment, the weighing of the crucible and crucible cover in the use of the process should not be tagged.
(2) Porcelain crucible can be placed in the mud triangle with alcohol lamp directly heated, heating the money to use the crucible clamp evenly rotation.
(3) Hot crucible should not be placed directly on the experimental table, on the asbestos net, and covered with a crucible lid or with the crucible cover to be moved into the dryer to cool.
9. Drip Bottle
A drop bottle is a container for adding liquids to the number of drops in the experiment. Commonly used as a drop bottle with a plastic head.
The drop bottle is composed of a frosted dropper with a rubber cap and a fine mouth bottle with an inner matte bottleneck. The most suitable for the storage of indicators and a variety of non-alkaline liquid reagents.
Drop bottle has white (or colorless), tan (or brown) 2 kinds, its specifications are expressed in volume size, commonly used for ML, $number ml, $number ml, such as several.
Usage considerations
(1) The brown drop bottle is used for dressing the liquid reagent of light and perishable.
(2) The Dropper is not interchangeable. The drop bottle cannot hold alkaline liquid for a long time, lest corrode, Bond.
(3) When using dropper to add liquid, the dropper can not be dipped into the container, so as not to contaminate the test fluid and bump the dropper tip.
(4) Rubber cap can not be absorbed after aging, to be replaced in time.
10. Weighing Bottle
A weighing flask is a container used to weigh solid reagents using an analytical balance. Often jilt has the high type and the low type 2 kinds.
The weighing bottles are fitted with frosted caps to ensure that the weighing is not scattered or contaminated.
The specification of the weighing bottle is expressed in the bottle diameter and the bottle high product. High-type weighing bottle commonly used 25 X 40 mm, 30 X 50 mm, 30 X 60 mm3 species, low type weighing bottle commonly used 25x25 mm, 50 X 30 mm and 60 X 30 mm3 species.
Usage considerations
(1) The lid and the bottle must be compatible with the use, avoid interchange.
(2) The weighing bottle must be cleaned, dried and cooled before being used for weighing.
(3) When weighing to use the clean and dry strong note surrounding the weighing bottle outside the wall to clip, strictly prohibited directly used to take the weighing bottle.
11. Reagent Bottle
Reagent Bottle is a laboratory dedicated to a variety of liquids, solid reagents container, the shape of the main has a fine mouth, wide mouth.
Because the reagent bottles are used only for room temperature storage reagents, they are usually made of sodium-calcium ordinary glass. In order to ensure a certain strength, the bottle wall is generally thicker. Reagent bottles In addition to the minute, wide mouth, there are colorless, tan (brown) 2 kinds, there are plug, no plug two categories. Among them, the glass stopper, regardless of the fine mouth, wide mouth, should have the internal grinding sand treatment process. Non-stopper can not be used for internal scrub, but with a certain size of the glass plug, such as rubber, plastic plug, cork and so on. In recent years, various kinds of practical plastic reagent bottles have been marketed, making this kind of container colorful.
The specification of the reagent bottle is indicated by the volume size, small to 30mL, 60mL, ranging from thousands of to tens of thousands of ML.
Usage considerations
(1) A plug reagent bottle is not used, to be in the cork and the mouth of the matte surface between the clip to prevent adhesion. As mentioned above, none of the reagent bottles can be used for heating.
(2) According to the physicochemical properties of the dressing reagent, the general principle of selecting the required reagent bottle is: Dressed solid reagent one by one selection of wide-mouth bottles, liquid reagents-Choose a fine mouth bottle, dressed in light easily decomposed or metamorphic reagent one by one selection of brown bottles, dressed in low boiling point volatile reagent one by one selected glass reagent bottles, dressing alkaline reagents a rubber plug reagent bottle and so on. If the reagent has the above-mentioned physical and chemical indicators, it can be considered according to the above principles, select the appropriate reagent bottle.
(3) Some special reagents, such as hydrofluoric acid can not be used in any glass reagent bottles and choose plastic bottles.
Container glass instruments, in addition to the above several, but also according to the different requirements of the liquid when the other two bottles, three bottles, four bottles, the bottle (also known as the Tap bottle) and other types of alternative.
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(iv) Separation of instruments
1, funnel
A funnel, also known as a triangular funnel, is an instrument used to separate a mixture of solids and liquids from a small-bore container by adding liquid or filter paper as a strainer.
Funnel has a short handle, long handle of the points, but all are round cone, the cone angle is generally in the 57 "between, projection schema is 13 angle shape, so called triangle funnel." As a cone is to ease the folding filter paper, in the filter and easy to keep the liquid in the funnel often have a certain depth, so as to maintain the filter on both sides of a certain pressure difference, beneficial filtrate through the filter.
In order to make filtrate through the time of filter paper, there are still some funnel in the cone wall system has several straight canal or curved canal, this kind of funnel also called the ripple Funnel. Middle school commonly used general Triangle funnel. Funnel specifications above the diameter of the mouth, commonly known as the MM, the mm and the more than 3.
Usage considerations
(1) filter, the funnel should be placed on the funnel rack, the bottom of the funnel handle to undertake the container wall, filter paper should be close to the funnel wall, filter paper edge should be lower than the funnel edge of about 5 mm, prior to wetting with distilled water to make no residual bubbles.
(2) Pour into the separation, the glass stick into the funnel, glass bar and filter paper three layer close. The liquid surface of the separating material is lower than the filter edge.
(3) The sediment in the funnel shall not exceed the height of the filter paper, so that it is easy to wash and precipitate after filtration.
(4) The funnel cannot be heated directly by fire. If a hot filter is required, the funnel should be placed in a metal heating jacket. If there is no metal jacket, the funnel can be used in advance with hot water immersion preheating.
2. Safety Funnel
The safe funnel is also called the long Neck funnel, which is used for adding liquids and is often used for assembling gas generators.
Safety funnel has straight shape, there are ring neck, ring neck single ball, ring neck double ball several. Its structure shows that one is because the neck is long, can accommodate more liquids, not to overflow, to avoid accidents, the second is the storage of liquid in the neck, the gas in the generator can play a safe role in liquid seals, it is called safety funnel. Safety funnel is generally the size of the bucket diameter, mm, full length about the MM.
Usage considerations
(1) Can not be heated by direct fire.
(2) When assembling gas generator, should be fitted with appropriate plug in the neck, long neck end should always remain immersed in the liquid below. When the generator is fitted, it is not necessary to dip under the liquid surface.
3, Liquid Funnel
The liquid funnel is used for controlling the liquid in the gas generator, and is often used in the separation of several liquid leopard without dissolving.
The liquid funnel has spherical, pear-shaped (or conical), cylindrical 3 kinds. Pear shape and barrel-shaped liquid funnel are used for liquid separation operation. The spherical liquid funnel is used in addition liquid and is often used for liquid separation.
The specification of the liquid funnel is indicated by the volume size, which is commonly used for 2 kinds of $number ml.
Usage considerations
(1) The use of the front glass piston should be coated with a thin layer of Vaseline, but not most, to avoid blocking the flow of liquid holes. When used, the left-handed Tiger resists the funnel ball and rotates the piston control liquid with the thumb index finger. At this point the small groove of the glass Plug and funnel mouth side of the small hole to align, then add liquid smooth.
(2) When the liquid is added, the bottom of the funnel cannot be submerged under the liquid surface.
(3) When oscillation, the small groove of the stopper should be closed with the dislocation of the side of the funnel orifice. When the liquid is split, the lower layer flows out from the funnel neck and the upper liquid is poured out from the funnel mouth.
(4) long-term use of liquid hopper, the piston should be added to the surface of a note to prevent adhesion. Use an oak bar to hold the piston to avoid loss.
4, Brinell funnel
The Brinell funnel is a kind of porcelain instrument used for decompression and filtration.
The cloth hopper is often matched with a suction filter bottle, which is used for filtering more solids.
The specification of the cloth funnel is indicated by bucket diameter and bucket length, commonly used for 20 X 60 mm, 25 X 65 mm, 32 X 75 mm.
Usage considerations
(1) Using the cloth funnel for decompression and filtration, the bottom of the funnel to put a slightly smaller diameter than the funnel filter paper, so that the bottom of the pores are all covered. In advance with distilled water wetting, especially to pay attention to the edge of filter paper and bottom close.
(2) The cloth hopper should be connected with a suction filter bottle with a suitable size and a single hole rubber stopper in the bucket neck.
5. Suction filter Bottle
The filter bottle is also called the filter bottle, which is equipped with the cloth funnel to make the filtrate container.
Suction filter Bottle wall thicker, can withstand a certain pressure. It with the cloth of the funnel after the general use of air or water suction pipe (also known as water pump, pump, common name water blowing) decompression. A two-port bottle is often used as a buffer between the suction pipe and the suction filter to prevent backflow.
Filter bottle specifications to volume, commonly used for $number ml, 500mL and $number ml and so on.
Usage considerations
(1) At the time of installation, the inclined mouth of the cloth funnel neck should be far away from and face the suction nozzle of the filter bottle. The speed of the filter is slow and uniform, and the filtrate cannot exceed the suction nozzle.
(2) in the process of drainage, if there is a crack in the funnel, the glass rod should be pressed and removed in time to ensure the low pressure of the suction filter bottle and easy to filter.
6. Drying Tube
A separator for drying gases or for removing impurities from a mixture of gases.
In addition to straight-type single ball, there are straight-shaped double ball, U-shaped tube, U-shaped tube, U-shaped tube with piston and so on. With the piston with a branch u-shaped drying pipe is very convenient to use, not when the piston can be closed, and to prevent dampness.
The specification of the drying pipe is indicated by the pipe diameter and length. For example, the common straight type single ball drying tube for 16 X 100 mm, 17 X 140 mm and 17 X 160 mn1 and so on.
Usage considerations
(1) The drying tube should be filled with solid desiccant. The desiccant should be selected according to the nature and requirements of the drying gas.
(2) When using straight-type drying tube, the desiccant should be placed in the ball body, at both ends should also be filled with a little cotton or glass fiber.
7. Wash the gas bottle
A washing cylinder is an instrument for removing impurities contained in a gas.
In the process of aeration bubbling, the gas containing impurities is passed through the liquid reagent selected in the washing cylinder. Impurities are washed away, while the gas contains a small amount of solid particles or droplets are also liquid reagent resistance to stay, and to achieve the purpose of purifying gas, the size of the washing cylinder is expressed in volume sizes, commonly used for $number ml, $number ml and 500mL several.
Usage considerations
(1) Suitable liquid detergent shall be selected according to the nature of the purified gas and the nature and requirements of the impurities contained. The amount of detergent generally does not exceed the volume of the washing cylinder.
(2) The air tightness of the washing cylinder should be inspected before use. Special attention should not be given to the incoming and out of the gas conduit connection.
(3) Wash the gas bottle can not be used for a long time to put alkaline liquid detergent, after use in a timely manner the detergent into a rubber plug reagent bottles for storage, and water cleaning and clean place.
8, Pan
Pan is a porcelain instrument used to evaporate, concentrate, or stir-fry solids.
There are 2 types of pan with handle and without handle. The middle school is usually pan with no handle. Pan specifications to the caliber, commonly used for the use of MM, the 2 of the five.
9, the Clay triangle
The clay triangle is a tool for placing crucibles when burning.
The clay triangle is made up of three wires, with three sections of enamel tube, shaped like a triangle and named after it. It has large, small points, depending on the size of the crucible.
Usage considerations
(1) used in conjunction with tripods.
(2) Not strong impact, lest damage porcelain tube.
10. Water bath Pot
The water bath pot is used for uniform and indirect heating, also can be used for temperature control experiment.
In order to avoid overheating or too much temperature change in the heating of direct fire, the heating methods such as water bath, steam bath or oil bath are often used. Water bath or steam bath can be heated to about 95 Shan. If the liquid injected in the bath is oil, it is called an oil bath.
The water bath pot has a copper or aluminum finished product. Its specifications to the caliber, often water bath pot for 160mm.
Usage considerations
(1) The liquid in the bath is volume. Its lid is a set of concentric circular cover group, each ring in the use should be wrapped with fine cloth or gauze, to avoid glass or porcelain containers and metal cover directly contact with overheating phenomenon. It also prevents the heat vessel from slipping.
(2) only heating under 80 Shan, the container heated parts can be immersed in water, but not contact the bottom of the bath. In the 80 Shan above, steam heating can be used. When heated above 100 Shan, the oil bath is replaced.
(3) If the laboratory has no water bath pot, the appropriate diameter of the beaker can be substituted, but the beaker should be heated when asbestos mesh.
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(vii) Supporting instruments, supplies
Supporting the type of instruments, supplies a wide variety, there are a variety of glass pistons, pipe fittings, two-pass, tee, rubber pipe. Rubber plugs and so on. Some supplies, a see then know the use. This is a brief introduction of rubber plugs and rubber tubes.
1. Rubber stopper
A rubber plug is a common accessory used to plug a container's mouth or to install other instruments after drilling. Plug material more, generally have glass, cork, rubber 3 kinds, in recent years also have a variety of plastic plug market. The use of the material plug, to be contacted by the matter to determine. If the plug can be used, the best choice is rubber plug, because it has a certain degree of elasticity, not only easy to process, and can make the instrument connected more firmly and tightly.
Laboratory General white Rubber plug specifications are the size of the end diameter and axial length from small to large in accordance with the number indicated that the smallest number No. 000, followed by No. 00 and No. 0, and then gradually from 1th number to 15th, the plug from small to large. The number of white rubber stoppers used in industry is even larger, and the larger the size of the cork and rubber stopper is, the larger the diameter of the slug is. The general large test tube is suitable for 3rd or 4th, and the flask is suitable for 5th or 6th rubber plugs.
Usage considerations
(1) General use of rubber plug, to make more than half of the rubber plug into the container appropriate. Use a rubber stopper and estimate that the hole will swell when it is inserted into the glass tube or container.
(2) gas, ether, benzene, carbon tetrachloride, carbon and other organic reagents and chlorine, liquid bromine, concentrated nitric acid and other inorganic reagents should not use rubber plug.
(3) Unused rubber plugs to be used, the use of talcum powder to be mixed with turtle bag sealed preservation, to prevent aging.
2. Rubber Hose
The rubber tube is used for connecting the instrument parts or transporting gas and liquid. Common rubber tube and medical latex tube 2 kinds. Middle School Laboratory more use of medical latex tube, the size of its diameter is indicated, commonly used 6 mm, 7 mm, 9 mm 3 kinds.
Usage considerations
(1) The use of the front glass piston should be coated with a thin layer of Vaseline, but not most, to avoid blocking the flow of liquid holes. When used, the left-handed Tiger resists the funnel ball and rotates the piston control liquid with the thumb index finger. At this point the small groove of the glass Plug and funnel mouth side of the small hole to align, then add liquid smooth.
(2) When the liquid is added, the bottom of the funnel cannot be submerged under the liquid surface.
(3) When oscillation, the small groove of the stopper should be closed with the dislocation of the side of the funnel orifice. When the liquid is split, the lower layer flows out from the funnel neck and the upper liquid is poured out from the funnel mouth.
(4) long-term use of liquid hopper, the piston should be added to the surface of a note to prevent adhesion. Use an oak bar to hold the piston to avoid loss.
4, Brinell funnel
The Brinell funnel is a kind of porcelain instrument used for decompression and filtration.
The cloth hopper is often matched with a suction filter bottle, which is used for filtering more solids.
The specification of the cloth funnel is indicated by bucket diameter and bucket length, commonly used for 20 X 60 mm, 25 X 65 mm, 32 X 75 mm.
Usage considerations
(1) Using the cloth funnel for decompression and filtration, the bottom of the funnel to put a slightly smaller diameter than the funnel filter paper, so that the bottom of the pores are all covered. In advance with distilled water wetting, especially to pay attention to the edge of filter paper and bottom close.
(2) The cloth hopper should be connected with a suction filter bottle with a suitable size and a single hole rubber stopper in the bucket neck.
5. Suction filter Bottle
The filter bottle is also called the filter bottle, which is equipped with the cloth funnel to make the filtrate container.
Suction filter Bottle wall thicker, can withstand a certain pressure. It with the cloth of the funnel after the general use of air or water suction pipe (also known as water pump, pump, common name water blowing) decompression. A two-port bottle is often used as a buffer between the suction pipe and the suction filter to prevent backflow.
Filter bottle specifications to volume, commonly used for $number ml, 500mL and $number ml and so on.
Usage considerations
(1) At the time of installation, the inclined mouth of the cloth funnel neck should be far away from and face the suction nozzle of the filter bottle. The speed of the filter is slow and uniform, and the filtrate cannot exceed the suction nozzle.
(2) in the process of drainage, if there is a crack in the funnel, the glass rod should be pressed and removed in time to ensure the low pressure of the suction filter bottle and easy to filter.
6. Drying Tube
A separator for drying gases or for removing impurities from a mixture of gases.
In addition to straight-type single ball, there are straight-shaped double ball, U-shaped tube, U-shaped tube, U-shaped tube with piston and so on. With the piston with a branch u-shaped drying pipe is very convenient to use, not when the piston can be closed, and to prevent dampness.
The specification of the drying pipe is indicated by the pipe diameter and length. For example, the common straight type single ball drying tube for 16 X 100 mm, 17 X 140 mm and 17 X 160 mn1 and so on.
Usage considerations
(1) The drying tube should be filled with solid desiccant. The desiccant should be selected according to the nature and requirements of the drying gas.
(2) When using straight-type drying tube, the desiccant should be placed in the ball body, at both ends should also be filled with a little cotton or glass fiber.
7. Wash the gas bottle
A washing cylinder is an instrument for removing impurities contained in a gas.
In the process of aeration bubbling, the gas containing impurities is passed through the liquid reagent selected in the washing cylinder. Impurities are washed away, while the gas contains a small amount of solid particles or droplets are also liquid reagent resistance to stay, and to achieve the purpose of purifying gas, the size of the washing cylinder is expressed in volume sizes, commonly used for $number ml, $number ml and 500mL several.
Usage considerations
(1) Suitable liquid detergent shall be selected according to the nature of the purified gas and the nature and requirements of the impurities contained. The amount of detergent generally does not exceed the volume of the washing cylinder.
(2) The air tightness of the washing cylinder should be inspected before use. Special attention should not be given to the incoming and out of the gas conduit connection.
(3) Wash the gas bottle can not be used for a long time to put alkaline liquid detergent, after use in a timely manner the detergent into a rubber plug reagent bottles for storage, and water cleaning and clean place.
8, Pan
Pan is a porcelain instrument used to evaporate, concentrate, or stir-fry solids.
There are 2 types of pan with handle and without handle. The middle school is usually pan with no handle. Pan specifications to the caliber, commonly used for the use of MM, the 2 of the five.
9, the Clay triangle
The clay triangle is a tool for placing crucibles when burning.
The clay triangle is made up of three wires, with three sections of enamel tube, shaped like a triangle and named after it. It has large, small points, depending on the size of the crucible.
Usage considerations
(1) used in conjunction with tripods.
(2) Not strong impact, lest damage porcelain tube.
10. Water bath Pot
The water bath pot is used for uniform and indirect heating, also can be used for temperature control experiment.
In order to avoid overheating or too much temperature change in the heating of direct fire, the heating methods such as water bath, steam bath or oil bath are often used. Water bath or steam bath can be heated to about 95 Shan. If the liquid injected in the bath is oil, it is called an oil bath.
The water bath pot has a copper or aluminum finished product. Its specifications to the caliber, often water bath pot for 160mm.
Usage considerations
(1) The liquid in the bath is volume. Its lid is a set of concentric circular cover group, each ring in the use should be wrapped with fine cloth or gauze, to avoid glass or porcelain containers and metal cover directly contact with overheating phenomenon. It also prevents the heat vessel from slipping.
(2) only heating under 80 Shan, the container heated parts can be immersed in water, but not contact the bottom of the bath. In the 80 Shan above, steam heating can be used. When heated above 100 Shan, the oil bath is replaced.
(3) If the laboratory has no water bath pot, the appropriate diameter of the beaker can be substituted, but the beaker should be heated when asbestos mesh.
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(vii) Supporting instruments, supplies
Supporting the type of instruments, supplies a wide variety, there are a variety of glass pistons, pipe fittings, two-pass, tee, rubber pipe. Rubber plugs and so on. Some supplies, a see then know the use. This is a brief introduction of rubber plugs and rubber tubes.
1. Rubber stopper
A rubber plug is a common accessory used to plug a container's mouth or to install other instruments after drilling. Plug material more, generally have glass, cork, rubber 3 kinds, in recent years also have a variety of plastic plug market. The use of the material plug, to be contacted by the matter to determine. If the plug can be used, the best choice is rubber plug, because it has a certain degree of elasticity, not only easy to process, and can make the instrument connected more firmly and tightly.
Laboratory General white Rubber plug specifications are the size of the end diameter and axial length from small to large in accordance with the number indicated that the smallest number No. 000, followed by No. 00 and No. 0, and then gradually from 1th number to 15th, the plug from small to large. The number of white rubber stoppers used in industry is even larger, and the larger the size of the cork and rubber stopper is, the larger the diameter of the slug is. The general large test tube is suitable for 3rd or 4th, and the flask is suitable for 5th or 6th rubber plugs.
Usage considerations
(1) General use of rubber plug, to make more than half of the rubber plug into the container appropriate. Use a rubber stopper and estimate that the hole will swell when it is inserted into the glass tube or container.
(2) gas, ether, benzene, carbon tetrachloride, carbon and other organic reagents and chlorine, liquid bromine, concentrated nitric acid and other inorganic reagents should not use rubber plug.
(3) Unused rubber plugs to be used, the use of talcum powder to be mixed with turtle bag sealed preservation, to prevent aging.
2. Rubber Hose
The rubber tube is used for connecting the instrument parts or transporting gas and liquid. Common rubber tube and medical latex tube 2 kinds. Middle School Laboratory more use of medical latex tube, the size of its diameter is indicated, commonly used 6 mm, 7 mm, 9 mm 3 kinds.
Usage considerations
(1) The use of latex tube, should be based on the size of the instrument, the diameter of the connection can not be too loose to avoid leakage or infiltration.
(2) to pipe fittings into the latex tube, you can first part of the pipe end of water wetting, and then the latex tube into the pipe diameter of the first half, and then with the fingers hard to set into, and around the rotating latex tube into a certain depth.
(3) Unused latex pipe Louboutin keep clean, dry, prevent aging bonding.
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(eight) Other kinds of instruments and supplies
1. Condenser
The condenser is also called a condensation tube, which is used to condense the vapor into liquid.
The condenser has different types of structure according to different usage requirements. The inner tube has a straight type (pictured), a serpentine and a sphere 3. The straight type condenser is simple in structure and is often used to condense the liquid with higher boiling point, and the Serpentine condenser is especially suitable for distillation and recovery of organic solvents with low boiling point and easy to defend the hair. And the sphere of two cases are applicable.
The size of the condenser pipe outside the casing length, commonly used for the MM, MM, $number mm, mm and $number mm and several other.
Usage considerations
(1) in the use of straight-shaped condenser, both tilt and upright, and the spherical or serpentine condenser can only be used upright, or because the ball effusion or condensate formed intermittent liquid column and the local liquid seal, resulting in the condensate can not flow out from the mouth.
(2) The direction of condensate water from the lower to the high, it must not be the water inlet and outlet (note: Cold water flow to the opposite direction of the steam flow).
2, should take over
should take over or call the receiver also known as the horn tube. It is used with the condenser, and the distillation liquid is imported into the container.
The corners to be taken over are about 105 and are easy to match with the 75 "angle of the distilled flask support tube, after which the two remain parallel."
should take over the specifications above the diameter and length of the said, commonly used for 18 mm, 25 X 180 mm and 30 X 200 mm 3 kinds).
Usage considerations
(1) When used, should take over the mouth and drilling sleeve in the condenser under the rubber plug combination.
(2) should be taken over by the depression points directly into the cone bottle and so on to undertake the container.
3, Plastic head dropper
The head dropper, also known as the glue cap dropper, is an instrument used for absorbing or dropping a small amount of liquid reagents.
The glue head dropper consists of a rubber cap and a glass dropper. There are straight-shaped (left), straight-shaped buffer ball (figure right) and the curved shape has a buffer ball and other forms.
The specification of the head dropper is Chang, which is commonly used as the $number mm and 2 kinds.
Usage considerations
(1) The Grip method is to use the middle finger and the ring finger to hold the glass tube part to maintain stability, and use the thumb and forefinger to squeeze the glue head to control the inhalation or drop of the reagent.
(2) When the glue head dropper is added to the liquid, it cannot reach the container.
(3) Can not be inverted, nor flat on the table. should be inserted in a clean bottle or in a test tube.
(4) Rinse immediately after use. It is forbidden to absorb another reagent without washing.
(5) Glue cap and glass dropper should be combined tightly not leak, if the rubber cap aging, to timely change.
4. Surface Dishes
The surface dish is often used to cover the container mouth to prevent liquid loss or solid spatter.
The surface dish is also used for the evaporation of a small amount of liquid in the heat flow, when the solid reagent is used as the container, and in analytical chemistry, 2 pieces of the same size of the surface dish are used as the gas chamber. Its specifications to surface diameter, commonly used for the $number mm and the 2.
Usage considerations
(1) When covering the container, the concave should be upward to avoid slipping.
(2) The surface dish cannot be heated directly by fire.
5. Dryer
The dryer is also called the Baogan device, which is a kind of instrument to keep the material dry.
Dryer has atmospheric pressure dryer (diagram) and vacuum dryer 2 kinds. The top of the vacuum dryer is connected with a suction tube and a gas suction machine. 2 kinds of dryers are divided into upper and lower 2 layers. The lower layer (also hit the bottom) put desiccant, in the middle of the hole porcelain plate, the upper layer (also the body) placed to dry substances.
General use of atmospheric pressure dryer, its specifications to the seat of the mouth diameter, commonly used for $number mm to $number mm and many other.
Usage considerations
(1) The lid of the dryer and the body of the mouth scrub part to be coated with a small number of any soil, so that the lid sliding several times to ensure uniform coating, when the cover is tight and not air leakage.
(2) Dryer in open, close the lid, the left hand hold the body, the right hand hold the cap "glass ball", along the body on the light push or pull. Do not lift up. The lid is removed and placed on the table, so that the glass ball is down, but pay attention to the lid scrolling.
(3) The material to be dried is first filled in the container, then placed on a perforated porcelain plate and covered with a lid.
(4) According to the nature of dry matter and desiccant drying efficiency of the selection of suitable desiccant placed in the container under the porcelain plate, the amount of about half of the container volume.
(5) When moving the dryer, both hands must be covered at the same time and the body, so as not to overturn the material and slide cover.
6. Bell Cover
The bell cover is designed to protect the dust from dust, or the glass instrument used for vacuum extraction.
The bell cover has a knot, a plug and a mouth and a piston dedicated to the vacuum of several.
Often have knot or have plug bell cover, its specification to inside diameter and height is indicated, commonly has 150x 250 mm, 180 X 250 mm, 200 X 300 mm and 250 X 400 mm several.
Usage considerations
(1) Glass clock cover can not be heated.
(2) The Glass Bell cover is also used in the closed experiment of poisonous substances, dilution of concentrated sulfuric acid, and the determination of air components.
7. Mortar
A mortar is an instrument used to grind a solid with little hardness.
The mortar has the common type (shallow type) and the high type (deep type) 2 kinds. Its material also because of the use and grinding of solid hardness of different iron, alumina, agate, porcelain and glass, and several other. A variety of research bowls are attached to the supporting pillars.
Commonly used porcelain or glass mortar, its specifications to the caliber, commonly used in the MM and the 2 of the five.
Usage considerations
(1) When lapping, the pestle shall rotate slowly and slightly under pressure in the bowl. Cannot be tapped up or down with the pestle.
(2) It is forbidden to use the mortar to grind the inflammable and explosive oxidizing agent.
Such instruments or supplies in addition to the above several, there are medicine spoons, hand-held punch, a variety of washing instruments and so on.
