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High School Chemistry Experiment Poetry
1. The use of pallet balances
The dial of the screw code, the pointer ruler has a tray. Adjust the screws up to balance, the matter code separation left and right side.
Take the code need tweezers clip, first big after small remember heart. The medicine cannot be put directly, the weighing is finished to restore.
Explain：
1, screw Travel Code scale, pointer ruler has tray: These two sentences said the main components of the pallet balance: (adjust 0 points of) screws, travel code, scale, pointers, trays (about two).
2, adjust the screws to achieve balance: it means that weighing before the balance should be checked first. If unbalanced, the screws should be adjusted to balance.
3, the matter code separation left and right side: "Thing" means the material weighing; Code "means the weight of the balance. It means that the weighing material should be placed in the left disk, and the weights should be placed in the right disk.
4, take the code need tweezers clip: This sentence means to take the weight, must not use the hand to take, and have to use tweezers clip.
5, the first big after small remember heart: meaning that in the addition of weights, should first clip the weight of mass, and then in the clip quality small weight (last move the code).
6, drugs can not be directly put: means that the weighing of drugs can not be placed directly on the tray (Lenovo: A piece of paper of the same size can be placed on each of the two pallets, and then the weighing drugs are placed on a slip, and damp or corrosive medicines must be weighed in a surface dish or beaker.
7, weighing finished to restore: meaning that after weighing, should put weights back into the weight box, the code to move back to 0, so that the balance back to the original state.
2. Filtration Operation Experiment
Bucket frame Beaker Glass bar, filter paper funnel angle. Before filtering to be static, three by two low don't forget.
Explain：
1, bucket frame Beaker Glass bar, filter paper funnel angle: "bucket" means funnel; Frame "means a funnel frame. These two sentences illustrate the instruments required for the filtration operation: funnel, funnel, beaker, glass rod, filter paper, and the angle of folding of the filter-paper to the angle of the funnel (so that the filter paper clings to the funnel wall).
2, before the filter should be static: it means that the liquid should be static for a moment before filtering, so that solids and liquids are fully separated.
3, three by two low do not forget: it means that in the filtration do not forget three on two low. "Three-by" means that the end of the funnel neck to rely on the filtrate of the beaker on the wall, to make the glass stick on the filter paper, the mouth of the beaker to rely on the glass rod; " Two low "means that the edge of the filter paper should be slightly lower than the edge of the funnel, the liquid surface of the filtrate should be slightly lower than the edge of the filter paper.
3. Distillation Operation experiment
The cold pipe is heated by the net, and the lower edge of the upper margin is flat. Need to add broken porcelain riot boiling, hot water reverse line.
Explain：
1, insulation heating cold pipe tilt: "Cold tube" this condensation tube. It means to separate the asbestos mesh when heating the distillation flask (to prevent the distillation flask from cracking because of uneven heat) and to tilt downward when installing the condenser tube.
2, the upper edge of the lower edge of two-phase flat: it means that the thermometer of the top edge of the mercury ball is exactly the same as the bottom edge of the bottle-tube interface at the same level.
3, hot and cold water reverse line: it means that the cooling water to flow from the bottom up, and the flow of hot steam in the opposite direction.
4. Extraction Operation Experiment
The extract liquid is insoluble and the degree of dissolution is different. Full oscillation and then static, decentralized on the inverted cut.
Explain：
1, extraction Agent liquid insoluble, the degree of dissolution is not the same: "Extract" means the extraction agent; Quality "means a solute. The two sentences mean that in the extraction Operation experiment, the principle of selecting extractant is that the solvents in the extractant and solution are not mutually soluble, the solubility of the solute in the extractant and the original solvent is not the same (the solubility in the extractant is greater than the solubility in the original solution).
2, full oscillation and then static: it means that in the extraction process to fully shock, so that the extraction is full, and then static solution layering.
3, the decentralization of the clear: the meaning of this sentence is to say that the lower part of the liquid funnel from the funnel foot, and the upper liquid to be poured from the funnel mouth
5. Preparation of mass concentration solution
Calculate the weighing step clear, the dissolution of the transfer of the volume. Room temperature washing Don't forget, shake the label will be the same.
Explain：
1, calculate the weighing steps clear, dissolve the transfer of the capacity: the meaning of these two sentences is that the process of preparing the mole solution is: calculation, weighing, (or quantity), dissolution, transfer, the volume.
2, room temperature washing do not forget: "room temperature" means that the dissolution of the solution is often due to the release of heat and the temperature rise, it must be cold to room temperature after the transfer fixed capacity. "Washing" means that after the liquid is removed, the beaker and the glass rod must be washed with distilled water (2-3 times), and the washing fluid is incorporated into the volumetric flask, and then the volume is fixed.
3, shake evenly the label will be completed: "Shake evenly" means to cover the cork, with the index finger to resist the cork, with another finger holding the bottom of the bottle, the capacity of the bottle inverted and shaking many times, so that the solution mixed evenly; Label "means to affix the label, indicating the concentration of the solution and the date of preparation.
6, Oxygen production experiment
Experiment first check gas tightness, heat evenly test tube tilt. Collect the common drainage method, remove the catheter and then move the light.
Explain：
1, the test first check gas tightness, heating uniform test tube tilt. "Test tube tilting" means that the installation of large test tubes, should make the test tube slightly inclined, that is, to make the test tube mouth below the bottom of the tube, so as to prevent heating drugs contained in a small amount of moisture into water vapor, to the pipe mouth condensation into a drip and backflow, resulting in test tube "Evenly heated" means that the test tube must be heated in a uniform way (Lenovo: The method is just beginning to heat, to use the hand to the alcohol lamp, to move back and forth, and so on after the test tube heated evenly and then fixed heating, so as to prevent the test tube local heating and burst).
2, the collection of common drainage method: means to collect oxygen to use drainage collection of gas method (Lenovo: To collect a gas if both the drainage method can also use the exhaust method, then the general selection of drainage method. Because the drainage method is higher than the purity of the gas collected by the exhaust method. The oxygen is heavier than the air, although it can be used by the upward exhaust method, but it is better to use the drainage method.
3. Remove the catheter and then move the light. It means that when you stop making oxygen, be sure to pull the trachea out of the sink and then remove the alcohol lamp (Lenovo: If the alcohol lamp is removed first, the temperature in the tube is lowered and the pressure is reduced, and the water will be sucked into the hot test tube, causing the test tube to burst with a sharp cooling).
7, methane production experiment
Sodium acetate alkali ash water without shadow, operation collection and oxygen. The ignition must be checked for purity, and the beaker is born.
Explain：
1, vinegar sodium alkali gray water no shadow: "Vinegar sodium" means sodium acetate; Alkali Lime. This means that you must use anhydrous sodium acetate and dry alkali lime reaction to produce methane (otherwise, if you use sodium acetate crystals or lime is not dry, you can almost not generate methane gas). [Lenovo: Can not directly use sodium hydroxide and anhydrous sodium acetate reaction, on the one hand, because sodium hydroxide is very easy to absorb moisture in the air; On the other hand, pure sodium hydroxide when heated to the glass test tube corrosive effect].
2, the operation of the collection and oxygen with: it means that the operation of the attention of the experiment and the collection method and oxygen exactly the same.
3, ignition must check purity: means that in the ignition of methane (like the ignition of hydrogen) first test its purity [Lenovo: If the methane is impure, mixed with some air will have the danger of explosion].
4, upper cover Beaker Shinusheng: means to cover a beaker over the flames, and soon see the water droplets on the inner wall. [Lenovo: Turn the beaker upside down, inject a small amount of clarified lime water into the beaker, shake, and the lime is cloudy.
8, ammonia production experiment
The ash-removing ammonium salt is hot ammonia, and the device is frank with oxygen. Alkali ash drying under the exhaust, pipe mouth need to block a group of cotton.
Explain：
1, ash-eliminating ammonium salt heat into ammonia: "ash" refers to the elimination of lime. It means that the lime and ammonium salts are commonly used in the laboratory to make ammonia.
2, the device with oxygen heart frankly: it means that the device and the device to make the same oxygen (the implication of the same note matters).
3, alkali ash dry exhaust: "alkali ash" refers to alkali lime. "Alkali ash drying" means that ammonia is usually made by drying ammonia by alkali lime during the experiment. "Under the exhaust" means that the collection of ammonia gas must be used downward air collection method (because ammonia is very easy to dissolve into water, and lighter than air). [Lenovo: (1) to be able to quickly get more pure ammonia, the trachea must be stretched into the bottom of the test tube; (2) The method of testing whether ammonia is filled with test tubes is: "The ammonia in the case of Phenolphthalein is Red", "two acid in the face of ammonia white smoke." ]
4, pipe mouth need to block a group of cotton: it means that the test tube to collect ammonia need to block a group of cotton [Lenovo: The role of blocking cotton is: (1) to prevent ammonia absorption of moisture in the air; (2) Increase the density of ammonia in the test tube. ]
9, hydrogen reduction copper oxide experiment
Hydrogen tests the pure test tube tilt, first through the hydrogen after the lighting. Black to red water droplets out, turn off the lights before stopping hydrogen.
Explain：
1, hydrogen test pure test tube tilt: "Hydrogen test pure" means that the hydrogen in the large test tube must first check the purity, otherwise there is a danger of explosion; The test tube tilting "means that in order to prevent the resulting water vapor from cooling back in the test tube, the test tube should be tilted (making the nozzle lower than the tube bottom).
2, first through the hydrogen after the lighting: it means that the experiment must first pass a hydrogen, waiting in the test tube after the air is discharged, and then light the alcohol lamp, or hydrogen and air mixture in the heat conditions will explode.
3, Black to red beads out: it means that the black powder (copper oxide) all into bright red (copper powder), at the same time the nozzle has a lot of water droplets appear, the reaction has been completely, so stop the experiment.
4, extinguish the lamp and then stop hydrogen: means to stop the experiment must first extinguish the alcohol lamp, after a while to cool the test tube and then stop the hydrogen. Otherwise, the air will enter the test tube, so that the reduction of copper and oxygen in the air under the conditions of heating, the oxidation reaction, the formation of copper oxide, so the experiment failed.
