(1) 1. Instrument that can be directly heated.
Instrument graphics and names, main uses, usage methods and precautions
The solvent or concentrate used for evaporation can be directly heat, but cannot be quenched. When evaporating the solution, it should not be too full, and the liquid level should be 1 cm from the edge.
Often used as a reactor, it can also collect a small amount of gas for direct heating. When taking the test tube, hold the tube mouth with the middle finger, forefinger and thumb, accounting for 1/3 of the total length. When heating, the test tube mouth should not be pointed at people. The liquid in the test tube shall not exceed 1/2 by volume, and the heated liquid shall not exceed 1/3. When heating, use a test tube holder and make the test tube form a 45-degree angle with the desktop. Heat all the liquid first, then heat it at the bottom of the liquid and shake it constantly. When heating solids, the test tube should be placed horizontally with the nozzle slightly inclined downward.
Used for burning solid, so that its reaction (such as decomposition) can be directly heated to high temperature. When burning, put it on the mud triangle and clamp it with crucible pliers. Condensation should be avoided.
Burning a small amount of solid matter can be directly used for heating. When it comes to substances that can react with copper and iron, it is necessary to spread fine sand or padded cotton wool in the spoon.
2. indirect heating is possible (asbestos mesh is required)
Instrument graphics and names, main uses, usage methods and precautions
(divided into 50, 100, 250,500, 1000ml, etc. ) is used to prepare, concentrate and dilute solutions. It can also be used as a reactor and heating test tubes in a water bath. When heating, it should be padded with asbestos mesh.
Choose beakers with different specifications according to the liquid volume.
When it is used as a reactor (especially when it is not heated), it cannot be directly heated, and it should be padded with asbestos mesh when heating. Not suitable for long-term heating. When there is too little liquid in the bottle, it is easy to break when heated.
The reactor for heating cannot be directly heated, but should be heated with asbestos mesh. The amount of liquid cannot exceed its volume 1/2.
Used for distillation and fractionation, and can also be used as a gas generator to pad asbestos mesh when heating. Other hot water baths can also be used.
Act as a receiver
Used as a reactor, often used in titration operation, generally heated on asbestos net. Liquid is not easy to overflow during titration operation.
3. Instruments that cannot be heated
Instrument graphics and names, main uses, usage methods and precautions
The upper opening for collecting and storing a small amount of gas is plane frosted, and the inner side is not frosted. Glass plates should be coated with vaseline oil to avoid air leakage. If there is a combustion reaction inside, producing solids, a small amount of water or fine sand should be added to the bottom.
All kinds of reagents are packed separately, and brown bottles are used when they need to be stored away from light. Wide-mouth bottles contain solids and narrow-mouth bottles contain liquids. The inside of the bottle mouth is frosted, which corresponds to the bottle stopper. Never cover it wrong. The glass stopper should not contain strong alkali, and the strong oxidant should not be placed in the dropping bottle for a long time.
Reactor solids+liquids used to make certain gases.
Solid block, small gas solubility, no strong exothermic reaction. Rotating the airway piston controls the progress or stop of the reaction.
(2) Measuring instruments
Instrument graphics and names, main uses, usage methods and precautions
When roughly measuring the volume of liquid, the appropriate size specification should be selected according to the measured volume to reduce the error. It cannot be used as a reactor or directly prepared as a solution.
(divided into 50 ml, 100 ml, 250 ml, 500 ml, 1000 ml) The solution used to accurately prepare a certain substance is not used as a reactor, cannot be heated, and the cork is not interchangeable, so it is not suitable for storing the solution. It should be used at the marked temperature.
Used to measure the volume of generated gas. Note: the gas to be measured is insoluble, and the intake pipe cannot be connected backwards, so it should be short in and long out.
For weighing drugs with low accuracy requirements, it is not allowed to put them directly in the tray, and the left objects are coded right. If the code on the left is correct, the mass is less than the actual mass of the substance. For example, the actual mass of 9.6g is 9-0.6 = 8.4g ... generally accurate to 0.1g.
Used in neutralization titration (also used in other titration) experiments, and can accurately measure the liquid volume. The acid burette should not contain alkaline solution and strong oxidant (KMnO4 solution, I2 water, etc.). ) should be placed in an acid burette with a "zero" scale at the top, accurate to 0.0 1ml.
Rubber-tipped dropper is used to suck or drop liquid and drop it in a fixed amount. It must be used exclusively, not for multiple purposes, and don't touch other containers when falling.
When used to measure temperature, it should not exceed its maximum range when heated, nor should it be used as a stirrer. Pay attention to the position of the mercury ball when measuring the temperature.
(3) Used as a liquid-containing instrument for filtration, separation and injection.
Instrument graphics and names, main uses, usage methods and precautions
When used for filtering or injecting liquid into a small mouth container for filtering, "one stick, two lows and three inclinations" should be achieved.
It is used to assemble the reactor and facilitate the injection of reaction liquid. The end of the long pipe should be inserted under the liquid surface to prevent gas from escaping.
Separating immiscible liquids with different densities; When the reactor is used for liquid separation, the lower liquid is discharged from the lower port and the upper liquid is poured out from the upper port; Not suitable for holding alkaline liquid.
(4) drying instrument
Instrument graphics and names, main uses, usage methods and precautions
Built-in solid desiccant or absorbent is used to dry or absorb some gases. Attention should be paid to prevent the desiccant from liquefaction and failure. Direction of airflow, big mouth in, small mouth out.
To remove impurities in gas, pay attention to the direction of gas flow, which should be the entrance of long pipe and the exit of short pipe.
Substances used to store dry substances or make dripping substances dry and hot should be cooled slightly before being put in.
(5) Other tools
Instrument graphics and names, main uses, usage methods and precautions
Used for distillation and fractionation, when liquefied gas is condensed, the pipe head is high and the tail is low, and steam and cooling water flow reversely.
As a heat source, the alcohol content in the flame at 500℃ ~ 600℃ should not exceed 2/3 of its volume, but it should not be less than 1/4. Use an external flame when heating. When it goes out, cover it with a lid and don't blow it out.
As a heat source, the flame temperature can reach about 1000℃, which is used in experiments requiring strong heat. Such as dry distillation of coal and carbon reduction of copper oxide.
It can be used as the lid of an evaporating dish or beaker, and it can be observed that the inside cannot be heated.
(6) Clamping instrument
Iron frame, iron clamp, test tube clamp, burette clamp, crucible clamp, tripod, mud triangle, tweezers, asbestos net, etc.
(7) Connecting instruments and supplies
Single-hole device, double-hole plug, non-hole plug, glass conduit, rubber tube.
There are also some instruments, such as glass rods, tube brushes, mortar and receivers.
Refer to Baidu library document "junior high school chemistry experiment device diagram of People's Education Press" for the diagram.
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