Thermometers can be divided into standard thermometers and practical thermometers according to their purposes and measurement accuracy. The standard thermometer has high accuracy and is mainly used to calibrate other thermometers. Practical thermometers refer to thermometers used for actual temperature measurement, mainly including experimental thermometers, industrial thermometers, meteorological thermometers, medical thermometers, etc. Rod industrial thermometer is commonly used in middle schools. The measuring range of alcohol thermometer is 100℃, and the measuring range of mercury thermometer is 200℃ and 360℃.
Precautions for use
(1) A thermometer suitable for the measuring range shall be selected. It is forbidden to use thermometers beyond the scope.
(2) When measuring the temperature of the liquid, the bubble of the thermometer should be completely immersed in the liquid, but should not touch the container wall. When measuring the steam temperature, the bubble should be higher than the liquid level, and when measuring the distillate temperature, the bubble should be slightly lower than the distillation bottle branch pipe.
(3) When reading, the line of sight should be flush with the highest point (mercury thermometer) or the lowest point (alcohol thermometer) of the meniscus of the liquid column.
(4) It is forbidden to use a thermometer instead of a glass rod for stirring. Wipe it clean after use, put it in a paper sleeve and store it away from heat sources. Pallet balance is an instrument used to roughly weigh the mass of substances, and each balance is equipped with a box of weights.
There are two kinds of loads commonly used in middle school laboratories: 100 g (sensitivity is 0. 1 g) and 200 g (sensitivity is 0.2g). Load, also called loading capacity, refers to the maximum weight that can be weighed. Sensitivity refers to the balance error (+/-). For example, a pallet balance has a sensitivity of 0. 1 g, which means that the error is 0. 1 g, so it cannot be used to weigh items with a mass less than 0.1g..
Precautions for use
(1) Before weighing, place the balance stably, move the traveling code to the zero point of the balance, and check whether the balance swings. If the balance has been reached, the number of squares on the left and right sides of the ruler indicated by the pointer swing is nearly equal. When the pointer is at rest, it should point to the center of the ruler. If the balance swings unevenly, you can adjust the left and right balance nuts to balance the swing.
(2) The weighed object cannot be directly placed on the tray, but a piece of paper with the same size should be placed on two trays respectively, and then the reagent to be weighed should be weighed on the paper. Wet or corrosive reagents must be weighed in a glass container (such as a mirror, beaker or weighing bottle).
(3) Put the weighed object on the left board, and put the weight on the right board. The weight should be clamped with tweezers. First add the weight with large mass, then add the weight with small mass, and finally move the code until the pointer swings to balance.
(4) After weighing, put the weights back into the weight box in turn. Move the roaming code back to zero. Specification: Test tubes are divided into ordinary test tubes, supporting test tubes and centrifugal test tubes. The specifications of ordinary test tubes are expressed in terms of outside diameter (mm)× length (mm), such as 5× 150, 18× 180, 25×200, etc. Centrifugal test tubes are expressed in milliliters. Main uses: ordinary test tubes are used as reaction containers for a small amount of reagents, collecting a small amount of gas and assembling small gas generators. Precautions for use: Ordinary test tubes can be heated directly. When filling solution, it shall not exceed 1/2 of the test tube capacity, and when heating, it shall not exceed 1/3 of the test tube capacity. When heating, a test tube clamp must be used, which is clamped near the test tube mouth. When heating, the test tube is heated evenly first, and then heated at the bottom of the test tube, and the test tube keeps moving. At this time, the test tube should be tilted about 45. When heating, use a test tube clamp, and the test tube mouth should not face the person, and the nozzle should not face the direction of the person. Heat evenly to avoid boiling or bursting of the test tube. It cannot be quenched after heating to prevent cracking. Main uses: (1) for holding liquid or solid reagents. (2) heating a small amount of solid or liquid. (3) making a few gas reactors. (4) Collect a small amount of gas. (5) Dissolve a small amount of gas, liquid or solid solute.
The test tube is used as a reaction container for a small amount of reagents, and can also be used to collect a small amount of gas. According to the use, test tubes are usually divided into flat-mouth test tubes, upturned test tubes and supporting test tubes. Flat-mouth test tubes are suitable for general chemical reactions, and flip-top test tubes are suitable for adding rubber plugs. A test tube with branches can be used as a gas generator, a gas cylinder or a small amount of still.
The size of a test tube is generally defined as the product of the outer diameter of the test tube and the length of the test tube, and commonly used ones are 10× 100mm, 12× 100mm, 15×l50 mm,18×/kloc.
Precautions for use
(1) Preheating before use:
(2) When using test tubes, the test tubes with appropriate size should be selected according to different doses. When using the test tube by hand, hold the upper edge of the test tube with thumb, food and middle finger. When swinging, keep your wrists and arms still:
(3) The heated liquid shall not exceed one third of the volume, and form a 45 "angle with the desktop. The nozzle shall not be aimed at yourself or others. To keep boiling, heat near the liquid level:
(4) To hold powdered reagents, the medicine spoon (or paper slot) should be sent to the bottom of the test tube. When loading granular solids, the test tube should be tilted so that granular substances can slowly slide into the bottom of the tube along the wall of the test tube;
(5) Holding the test tube should be at a certain distance from the nozzle. When heating, the outside of the test tube should be dry, and the test tube cannot be heated by hand. After heating, pay attention to avoid quenching to prevent cracking:
(6) When heating the solid reagent, the bottom of the tube should be slightly higher than the nozzle to prevent the condensed water from flowing back and bursting the test tube. After completion, it should continue to be fixed or placed on the asbestos net and let it cool naturally. When the amount of reactants is large, beakers are usually used as reaction containers. In addition, it is also used to prepare solutions, accelerate the dissolution of substances and promote the evaporation of solvents. There are many kinds and specifications of beakers, and low-type beakers are commonly used in middle schools. In order to add a certain amount of liquid in use, some beakers are printed with white volume marks on their outer walls. These beakers are called printed beakers and some are called graduated beakers. Its calibration is not very accurate, and the allowable error is generally 5%, so the word "approximate" is printed on the calibration table, which means "approximate volume", so it cannot be used as a measuring instrument. The specifications of beakers are differentiated by volume, and commonly used ones are 50 ml, 100 ml, 250 ml, 500 ml, etc.
Precautions for use
The solution in (1) beaker should not be too much, which is about 1/2 volume, but the solution should not exceed 1/3 volume when heating.
(2) The beaker can't be dry-burned, and it can only be heated for a long time when it is filled with liquid, but it must be padded with asbestos net.
(3) When holding a beaker, hold the outer wall and don't touch the inner wall with your fingers. Take out the beaker after heating and use the beaker clamp.
(4) When the solution in the beaker needs to be stirred with a glass rod, the glass rod should rotate evenly along the cup wall, and it is forbidden to hit the cup wall and bottom.
(5) Beakers should not be stored for a long time. Immediately after use, it should be cleaned, dried and stored upside down. As a container, the flask has more reactants and longer heating time, and the liquid participates in the reaction. Its bottleneck is small in diameter, and it is often used to generate steam or as a gas generator with plugs and necessary accessories. Flasks are widely used, so there are many kinds. There are two kinds of flasks commonly used in middle schools: round bottom flasks and flat bottom flasks.
A round-bottomed flask is usually used as a reaction vessel under heating conditions. Flat-bottomed flask is used for unheated gas generator, and is also commonly used for assembling and washing bottles. Because the bottom plane of the flat-bottomed flask is small, the edge is angular, and the force is large, it is easy to burst when heated. Therefore, it is generally not used in reaction vessels under heating conditions.
The specifications of the flask are differentiated by volume, usually 150 mL, 250 mL and 500 mL.
Precautions for use
(1) The bottom of the round bottom flask is uniform in thickness and has no edges, which can be used for long-term intense heating.
(2) When heating, the flask should be placed on an asbestos net and cannot be directly heated by flame.
(3) After the experiment, the heat source should be removed, and after standing and cooling, the waste liquid should be treated and washed. The distillation bottle belongs to the flask type, but the difference is that there is a slightly downward branch pipe at the bottleneck, which is specially used as a container for distilling liquid.
Distillation bottles can be divided into reduced pressure and normal pressure. The atmospheric distillation bottle also has branches at the upper, middle and lower parts of the bottleneck. For the distillation of liquid with higher boiling point, the distillation bottle with lower boiling point is selected, and the lower boiling point flows in the upper part. The branch pipe is located at the bottleneck and is usually used to distill liquids with ordinary boiling point.
The specifications of distillation bottles vary according to the volume, generally 150 mL and 250ml.
Precautions for use
(1) When configuring accessories (such as thermometers, etc. ), should choose the appropriate rubber plug, and pay special attention to check whether the air tightness is good.
(2) When heating, put it on the asbestos net to make it evenly heated. Conical bottles are also called conical bottles or triangular bottles.
This conical bottle has a big bottom and a small mouth. After the solution is filled, the center of gravity is low, which is very convenient for hand-held oscillation, so it is often used as a titration container in volumetric analysis. Laboratories also use it to assemble gas generators or wash bottles.
The size of conical bottles is differentiated by volume, and commonly used ones are 150ml, 250ml, etc.
Precautions for use
(1) When oscillating, hold the bottleneck with your right thumb, forefinger and middle finger, gently hold the lower part of the bottleneck with your ring finger, relax your wrist, and use your palm to drive your fingers to do circular vibration.
(2) When the conical flask needs to oscillate, the solution in the flask shall not exceed 1/2 by volume.
(3) If the liquid in the conical flask needs to be heated, it must be padded with asbestos net. Conventional type
Funnel is a cylindrical object used to inject liquid and fine powder into a container with a small inlet. The smaller tubular portion at the funnel mouth may have different lengths. Funnels are usually made of stainless steel or plastic, but paper funnels are sometimes used for substances that are difficult to clean thoroughly, such as engine oil. Some funnels are equipped with controllable valves at the mouth, and users can control the inflow speed of fluid. Sometimes filter paper is used to filter out chemicals, such as crystals.
Liquid separation type
A glass experimental vessel, in particular to a separating funnel for chemical experiments. Comprises a barrel body and a barrel cover covering the upper opening of the barrel body. A piston with a three-way structure is installed at the lower opening of the barrel body, and two ports of the piston are respectively connected with two lower pipes. By using the utility model, the experimental operation process is easy to control and the labor intensity is reduced. When the amount of liquid to be separated is large, there is no need to change the container. Just move the piston for three times, and the two liquids in the barrel can flow to the lower pipe at the same time. In junior high school, the main function of separating funnel is to control the rate of chemical reaction. The device is an experimental vessel with good performance in scientific research and chemical experiments.
Long neck type
A funnel is mainly used for adding liquid medicine during solid-liquid reaction in conical bottles. Generally, a separatory funnel can also be used instead.
When using, pay attention to that the bottom of the funnel is lower than the liquid level, which is to prevent the generated gas from escaping from the mouth of the long-necked funnel and play the role of liquid sealing. Long-necked funnel is used to make carbon dioxide and oxygen in laboratory. Note: It should be cleaned after the test, so as to avoid the deviation of the next test caused by drug residues.
A jar is a glass container for solid reagents, which is transparent and brown. Brown bottles are used to hold reagents (such as silver nitrate) that need to be protected from light. Wide-mouth bottles are generally used to store reagents, and the inside of the bottle mouth is frosted to match the bottle stopper.
Can't be used for heating.
When using the reagent, the bottle stopper should be inverted on the table, plugged tightly after use and sealed if necessary. Because the inside of the bottle mouth is frosted and equipped with a glass frosted plug, a jar with a glass plug cannot contain a strong alkaline reagent. If the alkaline reagent is contained, the rubber plug should be used instead, because the hydroxyl ion of the strong alkali reacts with the silicon dioxide in the glass, and the product makes the mouth stick to the rubber plug.
When placed, the label faces outward. Narrow-necked bottles are glass containers for liquid reagents, which are transparent and brown. Brown bottles are used to hold reagents that need to be protected from light. Small-necked bottles are generally used to store reagents, and the inside of the bottle mouth is frosted for bottle stoppers.
Can not be used for heating.
When taking the reagent, the bottle stopper should be put upside down on the table. When taking a large amount of reagent, directly pour the reagent into the container with the label facing the palm. When taking a small amount of reagent, use a dropper to drop it. Plug it with a back plug and seal it if necessary. Because the inside of the bottle mouth is frosted and equipped with a glass frosted plug, a jar with a glass plug cannot contain a strong alkaline reagent. If the alkaline reagent is contained, the rubber plug should be used instead, because the hydroxyl ion of the strong alkali reacts with the silicon dioxide in the glass, and the product makes the mouth stick to the rubber plug.
When placed, the label faces outward. Most of the burning spoons are riveted with iron wire and copper spoons. It is used to hold combustible solid substances for combustion test, especially the combustion reaction of substances in gas. When the burning spoon is used, if the substance (such as sulfur) contained in the spoon can react with iron and copper, it should contain a layer of fine sand.
Fine sand is spread in a burning spoon, just like the spoon we usually use. The sand is put in, but the spoon is always up, so the sand won't fall. The purpose of spreading sand is to spread a protective layer between the burning spoon and the medicine to prevent the medicine from corroding the burning spoon. The burning spoon is one of the instruments that can be directly operated on the alcohol lamp. Many experimental instruments can't be placed directly on alcohol lamps, such as beakers, flasks and conical bottles. Test tubes, crucibles, evaporating dishes and burning spoons are all instruments that can be used for direct heating. A container for evaporating concentrated solutions or burning solids. Big mouth and shallow bottom, round bottom and flat bottom with handle. The most commonly used evaporating dish is porcelain, but it is also made of glass, timely and platinum. Different materials have different corrosion resistance and should be selected according to the properties of solutions and solids. Good stability to acid and alkali, high temperature resistance, but not suitable for quenching.
There are two kinds of saucepans and saucepans, and the specifications are expressed in diameter, ranging from 60 to150 mm.
Main applications
Evaporate liquid, concentrate solution or dry solid matter.
It can withstand high temperature, but it can't be quenched. Take and put the evaporating dish with crucible pliers, and fix it with tripod or iron frame when heating. A large amount of liquid can directly contact the flame.
Precautions for use
(1) cannot be quenched after heating to prevent explosion.
(2) After heating, it cannot be directly placed on the experimental platform, but should be placed on the asbestos net to avoid scalding the experimental platform.
(3) If there is a large amount of liquid, it can be directly heated. If there is a small amount or viscous liquid, it should be padded with asbestos net or heated on the mud triangle.
(4) When heating the evaporating dish, keep stirring with a glass rod to prevent the liquid from splashing around when heating locally.
(5) After heating, it is necessary to move the evaporating dish with crucible pliers.
(6) After a large number of solids are precipitated, put out the alcohol lamp and use the waste heat to evaporate the remaining water.
(7) When heating, preheat with a small fire first, and then strengthen the heat with a large fire.
(8) Clamp the hot evaporating dish with preheated crucible tongs. Alcohol lamp is a kind of heating tool with alcohol as fuel, which is used to heat objects. Alcohol lamp consists of lamp body, wick tube and lamp holder. The heating temperature of alcohol lamp is 400-500℃, which is suitable for experiments with low temperature, especially without gas equipment.
A heating tool using alcohol (60%-75% ethanol solution, C2H5OH) as fuel is used to heat objects.
Composition: Alcohol lamp consists of lamp pot, wick, wick tube, alcohol and lamp holder.
Volume of alcohol lamp: 100ml, 150ml.
(1) An alcohol lamp consists of a lamp holder, a wick and a lamp pot filled with alcohol.
(2) The flame of alcohol lamp in normal use should be divided into three parts: flame core, internal flame and external flame. When heating, external flame should be used for heating. Recent studies show that the flame temperature sequence of alcohol lamps is: external flame >; Inner flame > flame center. Theoretically, it is generally believed that the external flame temperature of alcohol lamp is the highest. Because the outer flame is in full contact with the outside atmosphere, it is the easiest to exchange energy with the environment and release the most heat when burning, which leads to the temperature of the outer flame being higher than that of the inner flame.
(3) If the flame of the lamp is stable and the temperature rises appropriately, a metal mesh cover can be added.
The metal mesh cover can be made of scrap iron screen window.
Precautions for use
(1) It is absolutely forbidden to add alcohol to the burning alcohol lamp to avoid fire;
(2) It is absolutely forbidden to light another alcohol lamp with a burning alcohol lamp;
(3) After the alcohol lamp is used up, be sure to cover the lamp holder and do not blow it with your mouth;
(4) Don't knock over the alcohol lamp. In case spilled alcohol burns on the table, don't panic, cover it with a wet rag immediately;
(5) The alcohol in the alcohol lamp should not exceed 2/3 of the volume. German chemist R.W. Benson invented a gas-fueled heating device, which was used to equip the chemistry laboratory of Heidelberg University. Before bunsen burner's invention, the gas lamps used had bright flame, but the temperature was not high, which was caused by incomplete gas combustion. Benson improved it, so that the gas and air were fully mixed in the lamp first, so that the gas burned completely and a dim high-temperature flame was obtained. The flame is divided into three layers: the inner layer is a mixture of water vapor, carbon monoxide, hydrogen, carbon dioxide, nitrogen and oxygen, and the temperature is about 300℃, which is called the flame center. The gas in the middle layer began to burn, but the combustion was incomplete. The flame is light blue and the temperature is around 500℃, which is called reducing flame. The outer gas burns completely, the flame is lavender, and the temperature can reach 800 ~ 900℃, which is called oxidation flame. The temperature here is the highest, so the oxidation flame is used when heating.
Use steps:
1. Open the window of the laboratory, keep the air circulating and avoid strong light.
2. Connect the bunsen burner hose to the gas pipe and put it on the fire protection board.
3. First, turn off the air conditioner at the lamp holder and light a match at the air outlet.
4. Start the gas switch and light the lamp. At this point, the flame is orange.
Turn on the air conditioner to let fresh air in, the flame turns blue and the temperature becomes higher.
6. After use, close the air hole first, and then turn off the gas switch.
7. Pull bunsen burner out of the gas pipe. Measuring cylinder (measuring cylinder or graded glass) is a glass instrument used to measure liquids. A measuring cylinder is an instrument for measuring the volume of liquid. Specifications are expressed by the maximum energy capacity (ml), and commonly used ones are 10 ml, 25ml, 50 ml, 100 ml, 250 ml, 500 ml, 1000 ml, etc. The scale of the outer wall is in milliliters, each cell of the 1 0ml measuring cylinder represents 0.2ml, and each cell of the 50ml measuring cylinder represents1ml. It can be seen that the larger the measuring cylinder, the thicker the pipe diameter, the smaller its accuracy, and the greater the reading error caused by line-of-sight deviation. Therefore, the smallest measuring cylinder that can be measured at one time should be selected as far as possible according to the volume of the solution taken in the experiment. Graded measurement can also lead to errors. If measuring 70 ml of liquid, choose 100 ml measuring cylinder.
Precautions:
When reading (1), the line of sight is flush with the lowest point of concave liquid level.
(2) The measuring cylinder has no zero scale line.
(3) It cannot be heated and used as a reaction container. The wide-mouth glass container has a flat frosted bottle mouth, which can keep close contact with ground glass and is not easy to leak. Used for gas collection, gas cylinder assembly and reaction between substances and gases.
Matters needing attention
Cannot be heated
This instrument can't be heated, and it is easy to explode when heated. If heating is needed, a round bottom is needed.
Flasks and beakers.
Sprinkle with fine sand or water.
When the substance burns in a gas container, fine sand or water should be spread on the bottom of the bottle to prevent it from bursting.
Some substances can only be burned with sand, but not with water, such as Na. The spilled Na reacts with water to release hydrogen, which is easy to explode after being ignited.
tail gas treatment
If the combustion product contains polluting gas or smoke, it needs to be treated, such as covering the glass sheet after burning red phosphorus to prevent phosphorus pentoxide smoke from irritating the respiratory tract; Sulfur dioxide produced by sulfur combustion should be absorbed by sodium hydroxide solution at the bottom of the bottle. Glue dropper and common dropper. The former consists of a rubber nipple and a pointed glass tube.
use
Absorb or add a small amount of reagent, absorb the supernatant and separate the precipitate.
Matters needing attention
When dripping, the dropper should be vertical to the top of the container to avoid tilting and upside down.
Don't reach into the container or touch the container wall. The tip of the test tube should not touch other instruments except absorbing the solution to avoid being contaminated by impurities. You can't do two things at once.
Ordinary droppers need to be cleaned after use, but special droppers cannot be cleaned. They need special reagents to prevent pollution, and they can only be put back to the original reagent bottle after use.
When using, don't just hold it with your thumb and forefinger, but with your middle finger and ring finger. When the amount of liquid chemicals used at one time is small or dangerous, drop bottles are usually used to hold the solution. Usually liquid acid-base indicator is used for dropping bottles. The inside of the bottle mouth is frosted, similar to a narrow-mouthed bottle, and the bottle cap part is replaced by a dropper. Most containers used to hold a small amount of liquid are used in the laboratory.
Matters needing attention
1. The dropper on the dropper bottle is used together with the dropper bottle.
2. Don't rinse the dropper on the dropper bottle with water.
3. Do not store strong alkali (glass stopper) or strong oxidant for a long time.
4. The residual medicine sucked out can't be returned.
5. The dropper should not be placed upside down or horizontally, so as to avoid reagent corrosion of the dropper.
6. Don't put the dropper into the container when dropping medicine, so as not to pollute the dropper and damage the container. A flask is also called a flask or a flask (zèng). It is a practical and simple musical instrument with a long history. Except for the only one with a frosted glass stopper, the container and the curved neck are connected together, and the lines are smooth and in one go. It is used as a reaction vessel or still.
The biggest advantage of curved neck bottle is its simple structure. Can be connected to a glass container through a receiver, or can be directly connected to an inclined flask, without rubber plugs or rubber pipes, and is corrosion-resistant. For example, when making nitric acid in the laboratory, you can first put solid sodium nitrate into the plug, then add an appropriate amount of concentrated sulfuric acid, plug the cork and heat it slightly. The distilled nitric acid vapor directly enters the receiver through the curved neck and condenses into liquid. So as to avoid air leakage caused by nitric acid corrosion and aging of rubber products at the joint.
The specifications of curved neck bottles vary according to the volume, and commonly used ones are 125 mL, 250 mL and 500 mL.
Precautions for use
(1) If it needs to be fixed on the iron frame, the cork should be at the top, and the iron clip should hold the curved neck near the container, so that the curved neck naturally forms an angle with the desktop.
(2) When heating, it must be padded with asbestos net.
(3) After the experiment, it must be fixed and let stand. After it is cooled, the residue is poured out from the curved neck, and then water is added from the bottle stopper, washed and placed repeatedly. Watch glasses are made of glass, round and slightly concave in the middle, similar to an evaporating dish. It can be used to evaporate liquid, increase the surface area of liquid and accelerate evaporation. But it can't be heated like an evaporating dish. Can be used as a cover to cover the evaporating dish or beaker to prevent dust from falling into the evaporating dish or beaker; Can be used as a container to temporarily place solid or liquid reagents for easy access; It can be used as a carrier to carry the pH test paper, so that the acid or lye dripping on the test paper will not corrode the test bench.
Application mode
Watch glass should be cleaned and dried before use. Watch glasses are widely used, but no matter which instrument they replace, they should be used according to the use methods of various instruments. For example, when identifying the gas chamber, the gas chamber is synthesized by using the ground plane, two surface mirrors are attached to the upper surface mirror with test paper soaked with reagents, and the identified compound is placed on the lower surface mirror, heated if necessary, and the gas generated in the reaction is observed, and the gas is identified from the color change of the reagents. If white precipitation or turbidity is observed, you can stick a piece of black paper on the bottom wall of the mirror, and the white product can be clearly seen. If you cover all kinds of musical instruments, you only need to put them on the mouth of the musical instrument according to its arc shape and put them firmly, but you should pay attention to the selection of the watch mirror according to the caliber of the musical instrument. Generally, the diameter of watch glasses is larger than the instrument diameter ICm, which is more convenient to use. If you make a beaker cover, choose mirrors with different diameters according to the beaker capacity.
Matters needing attention
Can't heat.
Asbestos mesh is a wire mesh used on the tripod of alcohol lamp when heating liquid. It consists of two parts.
A piece of barbed wire is made of cotton cloth soaked in asbestos water to dry.
The flame will be concentrated somewhere in the container for a long time, and eventually the container will burst. With the asbestos net, the heat of the flame will be dispersed to every corner of the container, and the container will not burst when burned for a long time. Because asbestos is not a flammable substance, iron wire can disperse the heat of flame into the air and pass it to the top of the container, and the heat is uniform. In chemical experiments, a simple glass slender rod stirrer, also known as a glass rod, is used to accelerate dissolution in an evaporating dish, promote mutual dissolution, drain, dip in liquid and stir to prevent splashing caused by uneven heating. Especially in middle school experiments, it is the most commonly used and necessary experimental supplies.
function
1. Transfer liquid in case of filtration, etc.
2. Used for stirring during dissolution and evaporation.
3. Transfer of liquids and solids
4, filtration (drainage)
5. Initiate a reaction, such as igniting red phosphorus.
6. Evenly disperse the heat. The iron frame is used to fix and support various instruments, and the iron ring can be used instead of the funnel frame. Generally, it is often used in experimental operations such as filtration, heating and titration. It is one of the most widely used instruments in physical chemistry experiments. Usually used with alcohol lamp.
Usage: Support tool composed of iron plate and iron bar.
Usage: Experiments are often heated by long burette or beaker. At this time, it is necessary to put these devices at a suitable height with the help of an iron frame to facilitate the experiment. To support the burette, a burette clamp should be clamped on the iron frame, and the burette can be fixed by clamping on the burette clamp. When you put the beaker, you should clip an iron ring on the iron frame, put an asbestos net on the iron ring, and put the beaker on the asbestos net.
The burette is divided into alkaline burette and acidic burette. The former is used to measure liquid reagents that have corrosive effect on glass tubes; The latter is used to measure liquids corrosive to rubber. The burette capacity is generally 50mL, and each major scale is 1mL, and each major scale is divided into 10 minor scales, so each minor scale is 0. 1mL. The accuracy is one percent. It can be accurate to 0.0 1ml. The burette is a slender tubular container with a plug valve switch at one end and a scale indicator on it. Generally, the scale reading on the upper part is small, and the reading near the bottom is large. The mud triangle is made of three iron wires and covered with three plain-fired porcelain tubes, hence its name. It is divided into large and small, depending on the size of the crucible. Triangular brackets made of heat-resistant ceramic tubes and iron wires are used to support the crucible to heat and prevent cracking.
The mud triangle can withstand high temperature because it is wrapped by a heat-resistant ceramic tube, and the hollow pipe column can bear the load because there is an iron wire passing through it. When there is an object that needs bunsen burner heating, the mud triangle is usually placed on the iron ring as the support of the object. Or for experiments that need alcohol lamps to heat the crucible.
(1) is often used with tripod.
(2) Don't bump violently to avoid damaging the porcelain tube.