Use of chemical instruments and precautions: L. An instrument that can be heated

  (l) a container used in a small amount of drugs, at room temperature or in a heating condition, for a small amount of reagent reaction, which can be used to make or collect a small amount of gas.

  Precautions to use: Shan can be directly heated, with a test tube clip at 1/3 from the test tube.

  Shan placed in the test tube of the liquid, not heating when not exceeding the test tube volume of L 2, heating not more than L 3.

  Shan heating can not be sudden cold, prevent burst.

  When Shan is heated, the test-tube mouth does not respond to anyone;

  (2) The beaker is used as a reaction vessel for preparing solution and a larger reagent, at room temperature or heating.

  Precautions for use: Shan should be placed on the asbestos net when heated to make the heating even.

  When the Shan dissolved substance is stirred with a glass rod, it cannot touch the cup wall or the bottom of the cup.

  (3) Flask is used for large reagent and liquid substance to participate in the reaction container, can be divided into round bottom flask, flat bottom flask and distillation flask. They can be used to assemble gas generator. A distillation flask is used for distilling to separate mutually miscible substances of different boiling points.

  Precautions to use: Shan round bottom flask and distillation flask can be used for heating, to pad the asbestos net when heating, or to other hot bath (such as water bath heating, etc.).

  The amount of Shan liquid should not exceed 1/2 of the flask volume.

  (4) Pan is used for evaporating liquid or concentrated solution.

  Precautions to use: Shan can be heated directly but not chilled.

  The Shan liquid quantity should not exceed 2/3 of the pan volume.

  Shan pan should use crucible clamp.

  (5) The Crucible is mainly used for high temperature burning of solid material.

  Precautions to use: Shan The Crucible on a tripod to heat directly on the clay triangle.

  The Crucible clamp is used when the Shan is taken and placed.

  (6) The heating heat source commonly used in chemical experiment of alcohol lamp.

  Precautions to use: Shan the wick of the alcohol lamp to be flat.

  Shan add alcohol, no more than 2/3 of the alcohol lamp volume, alcohol not less than $number.

  Shan absolutely forbid to add alcohol to the burning alcohol lamp to avoid fire.

  Shan absolutely forbids the use of alcohol lamps to ignite another alcohol lamp.

  Shan Use the alcohol lamp, must use the lamp cap to extinguish, cannot use the mouth to blow.

  Shan do not touch the alcohol lamp, in case the spilled alcohol burns on the table, should immediately cover with a damp cloth.

  2. Instrument of the separation of substances

  (1) Funnel is divided into common funnel, long neck funnel and liquid funnel. A common funnel is used to filter or transfer liquids to a small mouth container. A long neck funnel is used to inject liquids into a gas generator. The liquid funnel is used for separating different liquids with different densities and immiscible, and can be used to add liquid to the reactor at any time. Also used for extraction separation.

  (2) The general use of the bottle, cone-shaped bottle or large-test tube assembly. A liquid in a washing cylinder used to wash gas, except

  Go to one of the moisture or other gaseous impurities. Use to pay attention to the flow of gas, generally "grow short".

  (3) The dry tube is filled with a solid, used to wash the gas, remove the moisture or other gas impurities, you can also use U-shaped tube.

  3. Measuring instruments

  (l) The pallet balance is used for the weighing of the high precision requirements, and can be weighed to 0.1g. The attached weights are the standard of weighing material quality on the balance.

  Precautions to use: Shan weighing before the balance to be smooth, the tour is placed in the scale 0, adjust the balance of the left and right of the nut, so balance.

  Shan weighing the weighing in the left disk, weight on the right side. Weight to use tweezers clip, first add the weight of the mass, and then add the weight of small weights.

  Shan weighing dry solid drugs should be placed on paper.

  Shan susceptible, corrosive medicines (such as sodium hydroxide) must be weighed in glassware.

  After weighing the Shan, the weights should be put back in the weight box and the code is moved back to 0.

  (2) cylinder is used to measure the volume of liquids and is not accurate.

  Precautions to use: Shan can not be heated and the volume of hot liquid, can not be a reaction vessel, can not dilute the solution in cylinder.

  When the liquid is Shan, the cylinder must be flattened, and the line of sight shall be kept at the lowest level of the liquid surface of the cylinder, and then the volume of the liquid will be read.

  A measuring cup, a utensil for measuring liquids.

  (3) The volumetric flask is used to accurately prepare a certain volume and a certain concentration of solution. Check to see if it leaks before use. The solution is transferred to the volumetric flask by means of a glass rod drainage.

  Precautions to use: Shan can only be prepared on the capacity of the volume of liquid bottles.

  The volume of the Shan capacity bottle is calibrated at 20 Shan, and the temperature of the solution transferred to the bottle should be around 20 Shan.

  (4) Burette is used to accurately measure a certain volume of liquid. The burette with the glass piston is acid type burette, and the burette of the rubber tube with the inner glass ball is the alkali burette.

  Precautions to use: Shan acid type, alkali type Burette can not be mixed.

  The estimated readings for S. 25ml and 50mL Burette are Biong. 01mL.

  Shan before filling liquid with lotion, water in turn rinse clean, and to be installed with the solution run wash burette.

  When the Shan adjusts the liquid surface, the tip portion of the dropper should be filled with solution so that the liquid surface remains at "0" or

  A certain scale below "0". The view is maintained horizontally with the most concave point of the liquid surface in the tube.

  (5) The volume gas device can be assembled from the jar and cylinder. As shown in the figure. The volume of the water in the cylinder is the volume of the gas produced by the temperature and pressure. Suitable for measuring the volume of gas insoluble in water.

  Other: Pan

  There are two kinds of sessile pan and handle pan, the specification is indicated in diameter, and there are 60 150mm and so on.

  Main use: evaporation liquid, concentrated solution or dry solid matter.

  Precautions to use: the ability to heat, but not sudden cold, the amount of liquid can be directly heated on the flame evaporation. When the amount of liquid is small or sticky, the asbestos net should be heated.

  Pan mainly used in distillation and other operations, is an ideal chemical distillation equipment

  Surface Dishes

  The surface dish is made of glass, round shapes, slightly concave in the middle, similar to pan. Can be used to do some evaporation liquid work, it can increase the surface area of the liquid, thereby speeding up evaporation. But not as hot as pan. Can make lid, cover on pan or beaker, prevent dust from falling into pan or beaker, can be used as container, temporarily put solid or liquid reagent, easy to use, can be used as bearer, to carry ph test paper, so that the acid liquid or lye dripping on the test strip does not corrode the test bed.

  Make a summary on the other hand

  A: Can not be heated: cylinder, gas cylinder, funnel, thermometer, drip bottle, surface dish, wide mouth bottle, fine mouth bottle, etc.

  B: Can be directly heated: test tube, pan, crucible, burning spoon

  C: Indirect heating: beaker, flask, cone bottle

  (1) test tubes commonly used to Shan a small number of reagents of the reaction vessel Shan can also be used to collect a small amount of gas container Shan or to plant a small gas generator

  (2) The beaker is mainly used for Shan dissolved solids, confecting solutions, and dilute, concentrated Shan of solution can also be used to do a larger amount of reaction between substances

  (3) Flask-------round bottom flask, flat bottom flask

  Shan is commonly used to do a large amount of liquid between the reaction Shan can also be used as a device gas generator

  (4) Cone-shaped bottle is often used for Shan heating liquids, Shan can also be used to plant gas generators and bottle washer Shan can also be used in titration of the drop containers.

  (5) Pan are usually used for concentrating or steaming the solution.

  (6) The plastic head dropper is used for removing and dropping a small amount of liquid.

  Note: Shan is used when the glue head is on, nozzle below (prevents liquid reagent from entering the rubber head and causes the rubber head to corrode or to bring the impurity in the gum heads into the test liquid Shan the dropper nozzle can not reach the drip containers (prevent the dropper from being stained with other reagents) Shan should be washed immediately after use and inserted in a clean test tube, without washing the dropper is prohibited from absorbing other reagents Shan drip the dropper on the bottle must be matched with the drop bottle

  (7) cylinder is used to measure a volume of liquid.

  Can not be Shan in cylinder dilute or confecting solution, must not be heated to cylinder.

  And not Shan in cylinder.

  Note: In the volume of liquid, according to the volume to choose the appropriate size of the cylinder (otherwise it will cause greater error), the reading should be cylinder vertical stationary on the table, and the cylinder scale and cylinder in the liquid concave surface of the lowest point to maintain the same level.

  (8) Pallet balance is a weighing instrument, generally accurate to 0.1 grams. Note: The weighing in the left disk, weight in order from big to small in the right disk, the use of weights to use tweezers, can not be directly with the hands, scales can not be weighed hot objects, said objects can not be placed directly on the pallet, to be on both sides of the first quality paper, easy to hygroscopic drugs or corrosive drugs (such as sodium hydroxide solids) must be placed in the glass weighing.

  (9) Shan for collecting or storing a small amount of gas Shan can also be used for the reaction of certain substances and gases.

  (the mouth is frosted)

  (10) Wide-mouth bottle (the inner wall is frosted) is often used to hold solid reagents, can also be used as a washing cylinder

  (11) The fine mouth bottle is used for holding liquid reagent, the brown fine-mouth bottle is used to dress up the material needing to avoid the light preservation, the reagent bottle application rubber plug when depositing alkali solution, cannot use the glass plug.

  (12) The funnel is used for injecting liquids into a fine-mouth container or for filtering devices.

  (13) long neck funnel is used to inject liquid into the reaction vessel, if used to make gas, then the lower end of the long neck funnel should be inserted below the liquid surface to form "Liquid seal" (prevent gas escaping from the long neck bucket).

  (14) The liquid funnel is mainly used for separating two kinds of liquids which are immiscible and different in density, and can be used to drop liquid in the reaction container, which can control the dosage of the liquid

  (15) The test tube clamp is used for holding the test tube, heating the test tube, using the bottom of the test tube, and clamping in the middle and upper part of the test tube.

  (16) The iron stand is used for fixing and supporting a variety of instruments, often used for heating, filtration and other operations.

  (17) Alcohol lamp Shan before use to check rushes, absolutely forbid to add alcohol to the burning alcohol lamp

  Shan also can not use the burning alcohol lamp to ignite another alcohol lamp (lest fire)

  Shan alcohol lamp Wei The highest, should be heated in the Wei part preheating after heating.

  Shan to prevent wick contact with hot glassware (to prevent damage to glassware)

  At the end of the Shan experiment, the application of the lamp cap (lest the alcohol volatilization in the lamp and make the rushes leave too much water, not only waste alcohol but also not easy to ignite), must not be blown out by the mouth (otherwise it may cause alcohol burning in the lamp, dangerous)

  Shan If alcohol burns on the table, cover with a damp rag immediately.

  (18) The glass rod is used for stirring (accelerated dissolution) transfer such as ph determination.

  (19) Burning key

  (20) Thermometer has just used the high-temperature thermometer can not be immediately washed with cold water.

  (21) The medicine Spoon uses the powder or the small granular solid medicine, each time must use the medicine spoon to wipe the clean filter paper.

  2: Basic operation

  (1) The use of drugs: "Three no" Shan not to touch drugs with hands Shan not to taste the taste of drugs Shan not to put the nostrils to the mouth of the container to smell the smell

  Note: The medicine that has been removed or left behind cannot be returned to the original reagent bottle and should be returned to the laboratory.

  A: access to solid drugs

  The use of block solid tweezers (concrete operation: first put the container horizontally, put the medicine into the container mouth, then the container is slowly erected up); Use a powder or small granular medicine to use a spoon or paper trough (Specific operation: first, the test tube horizontal, the medicine spoon or paper tank carefully into the bottom of the test tube, and then make the test tube upright)

  B: The use of liquid medicine

  The use of a small amount of plastic head dropper can be used to get a lot of dumping directly from the reagent bottle (note: Put the cork upside down on the table, the label to the palm of the hand, to prevent contamination or corrosion of reagent labels, the test tube, so that the mouth next to the tube mouth)

  (2) The heating of the material can be used in a tube, a flask, a beaker and a pan;

  A dry test tube, pan, crucible can be used for solid heating.

  A: The test tube in the liquid heating in general and the table into a 45 angle, first preheating after the concentration of the bottom of the test tube heating, must not be heated to anyone

  B: To heat the solids in the test tube: The test tube should be slightly downward (to prevent the water from flowing back to the bottom of the tube, so that the test tube rupture) Preheat and then concentrate the medicine to heat

  Note: The external wall of the instrument heated cannot have water, dry before heating, lest the container burst; when heated, the bottom of the glass instrument cannot touch the rushes of the alcohol lamp to prevent the container from bursting. Hot-burning containers cannot be immediately rinsed with cold water or placed on the desktop immediately and should be placed on the asbestos net.

  (3) Filtration is a method of separating insoluble solids from liquids (i.e., a solution, insoluble, must be filtered), such as coarse salt purification, potassium chloride and manganese dioxide separation.

  Operation points: "One paste", "Two Low", "three-by"

  "One paste" means the filter paper with water wetting should be close to the funnel wall;

  "Two paper" refers to the edge of the filter edge slightly lower than the Shan filtrate surface of the filter edge of Shan.

  "Three-by" means the Shan beaker close to the glass bar Shan Glass bar close to the three-layer filter paper Edge Shan funnel end close to the beaker inner wall

  (4) The Assembly of the instrument, generally from low to high, from left to right in the order.

  (5) The tightness of the inspection device is first immersed in the water, then with the palm fastening the wall (phenomenon: the tube mouth bubbles out, when the hand left after the formation of a water column.)

  (6) Glass instrument washing, such as the instrument with insoluble alkali, carbonate, oxides, etc., can be added acid washing, and then rinse with water. If the instrument with grease and other available hot soda solution washing, can also use detergent or powder scrub. Clean the standard is: the instrument inside the wall of water that does not gather into a water droplets, also do not shed, and evenly attached to a layer of film, it is clear that the washing has been clean.

  (7) methods of dealing with common accidents

  A: The use of alcohol lamp, inadvertently caused by alcohol burning, should immediately use a damp rag.

  B: The acid spills carelessly on the table or the skin uses the sodium bicarbonate solution flushing.

  C: Alkali solution accidentally sprinkle on the table using acetic acid rinse, accidentally sprinkle on the skin using boric acid solution rinse.

  D: If the concentrated sulfuric acid spill on the skin must not first with a large amount of water rinse.

  3. Preparation and collection of gases

  (1) The occurrence device of common gas

  A: The reaction between solids and need to be heated, the use of O2 devices (NH3, CH4); Be sure to use the alcohol lamp.

  (2) Methods of collecting common gases

  A: The drainage method is suitable for the gas which is difficult or insoluble in water and does not react with water, the catheter is dipped into the bottle, (Co, N2, no can only use drainage method)

  B: The upward air method is suitable for gases with higher density than air and not reacting with air (CO2, HCL can only use up air method)

  C: The downward air method is suitable for gases with less density than air and not reacting with air

  Exhaust method: The catheter should be dipped into the bottom of the bottle

  4. The gas is fully inspected:

  O2 's full: With the wood with the embers on the bottle.

  CO2 's full: With the burning wood in the mouth. The method of proving CO2 is used to clarify lime water.

  9, (1) The test-tube clamp should be sandwiched in the middle and upper part, the iron clip should be sandwiched from the test tube mouth 1/4.

  (2) When heating, the liquid in the test tube should not exceed 1/3 of the test tube volume, and the liquid in the test tube does not exceed 1/2 of the test tube volume.

  (3) The use of flasks or conical bottles should not exceed the volume of 1/2 of their volume, evaporation solution should not exceed the amount of pan volume of 2/3; alcohol lamp alcohol must not exceed its volume of 2/3, nor less than 1/4 of its volume.

  (4) in the test tube, the water in the tube is 1/2 (half tube water), and the liquid in the washing cylinder is 1/2 of the bottle; if there is no indication of dosage should take a small amount, the liquid to take 1--2 ml, the solid as long as the bottom of the test tube, the test tube in the liquid, the general and desktop into the 45 angle, heating the tube in the solid, the tube mouth slightly downward tilt.