3. Sequence of metal activity
Order of metal mobility
The order of activity of common metals (represented by element symbols).
k ca na mg al zn fe sn pb（h）cu hg ag pt au
The activity of the metal gradually decreases from strong.
[Clever Learning].The order of metal activity "potassium, calcium, sodium, magnesium, aluminum, zinc, iron, tin, lead, hydrogen, copper, mercury, silver, platinum" can be memorized by the homophonic method, that is, "marry that beautiful woman, the body is slender and light, and a total of 100 catties".
Determination of the order of activity of metals
** of the order of metal activitySee Experimental Breakthrough for details
Application of the order of metal activity
1) It is used to judge the strength of the metal's mobility: the higher the position of the metal, the stronger its activity.
2) Determine whether the displacement reaction can occur and how violent the reaction is.
Metals in front of hydrogen can react with dilute hydrochloric acid or dilute sulfuric acid, and the higher the position, the more intense the reaction; The metal that comes behind the hydrogen cannot react with dilute hydrochloric acid or dilute sulfuric acid.
Metals in the front (except K, Ca, and Na) can displace metals in the back from their salt solution.
3) According to the reaction between the metal and the salt solution, judge the composition of the filtrate and filter residue. When a variety of metals are put into a salt solution of one metal or a metal is put into a mixed salt solution of multiple metals, the reaction follows the rule of "displacement first at a distance (the farther the interval, the priority reaction)" in addition to the principle of "before and after".
Fourth, the smelting of metals
Metal Resources
1) Distribution and form of existence: Metal resources on the earth are widely present in the earth's crust and oceans, except for a few very inactive metals such as gold and silver in the form of elemental substances, the rest exist in the form of compounds.
2) Common iron ore.
[Special Reminder].Metals are non-renewable and should be exploited wisely.
Carbon monoxide reduces iron oxide
1) Principle: Fe2O3 3CO
2fe＋3co2。
2) Device. 
3) Sequence of operations.
Check the airtightness of the device;
The iron oxide powder is loaded into a glass tube and fixed on the iron frame;
Lighting the alcohol lamp at the right end: prevents the release of carbon monoxide that is not involved in the reaction into the air and causes pollution;
Introduce carbon monoxide to the glass tube: in order to drain the air in the device and prevent the carbon monoxide and air from mixing and heating**;
lighting an alcohol blowtorch to heat a glass tube filled with iron oxide;
Stop the heat, extinguish the alcohol blowtorch;
stop the introduction of carbon monoxide;
Turn off the alcohol lamp at the right end.
【Summary】Carbon monoxideGo out early and return late, alcohol blowtorchArrive late and leave early
4) Phenomenon: The red solid in the glass tube turns black, the clarified lime water in the test tube becomes turbid, and there is a blue flame at the tip of the glass catheter.
5) Tail gas treatment: carbon monoxide is toxic and cannot be directly discharged, so there must be an exhaust gas treatment device in the experimental device. In addition to the alcohol lamp shown in the picture, a balloon can be tied to the pointed mouth to collect carbon monoxide.
6) Precautions.
There is air inside the unit, and a mixture of carbon monoxide and air is heated, which can occur**. Therefore, carbon monoxide should be introduced first, and the air in the installation should be exhausted before lighting the alcohol blowtorch.
After the experiment, if the carbon monoxide is stopped immediately, the pressure in the device is reduced, and the air enters the rigid glass tube, which will cause the reduced iron powder to be oxidized again, and at the same time, the lime water is sucked into the hard glass tube, which will cause the hard glass tube to burst. Therefore, carbon monoxide should be continued until the unit has cooled down to room temperature.
5. Iron rust and protection
Rust conditions of iron products**
Precautions] aThe water used in the experiment is distilled water that has been boiled and rapidly cooled, the purpose of boiling is to remove the oxygen dissolved in the water, and the purpose of rapid cooling is to reduce or prevent the oxygen in the air from dissolving in the water; b.The purity of iron, the temperature of the environment, acidity and alkalinity, etc., are also factors that affect iron rust.
Special reminder] The main component of rust is Fe2O3; Rust is loose and porous, and it does not prevent the iron inside the iron from continuing to react with O2 and water.
Anti-rust measures
1) Keep the metal surface clean and dry. For example, wipe the kitchen knife dry and hang it after use.
2) The metal surface is coated with a protective layer. Such as: painting, oiling, electroplating, etc.
3) Change the single structure of the metal element to make an alloy. Such as: stainless steel.
Protection of metal resources
1) Prevent the corrosion of metal.
2) Utilization of metals.
3) Minerals should be exploited in a planned and rational manner, and indiscriminate mining without regard to national interests is strictly prohibited.
4) Look for alternatives to metal.
Techniques. 1. The color characteristics of copper are an important feature of copper, and it is often the "problem" of problem solving, especially inference.
2. When some metals are in a powder state, they will show different colors; For example, powdered iron powder is all black, mainly because the particles are too small for light to reflect easily.
3. The surface of iron products used in life generally has a gold-plated layer or paint, which is not its true color. The color of the cross-section can be observed.
4. The alloy is a mixture, and all components in the alloy exist in the form of elemental substances, such as copper and zinc in brass. The key to judging whether a substance is an alloy is to see whether it contains metal components, and the alloy requires at least one metal in the composition.
5. The reaction between the substance and oxygen, mainly pay attention to the selection of reaction conditions and the description of experimental phenomena, in the description of experimental phenomena, be careful not to say the name of the product, so that it is not a phenomenon but a conclusion.
6. Key points of the reaction between metal and acid:
The reaction of the metal with the acid is exothermic.
After the metal reacts with the acid, the mass of the solution increases.
When Fe participates in the displacement reaction, it can only produce +2 ferric salts.
7. Key points of the reaction between metals and salts:
Such reactions must be carried out in solution, and water-insoluble compounds generally do not react with metals.
K, Ca, and Na are very active, but they cannot be used to replace the metals in the compound because they can react violently with water in solution. Potassium, calcium, and sodium react with water to form alkali and hydrogen, and then alkali reacts with salt.
CuSO4 solution: blue, FeSO4, FeCl2 solution: light green. When Fe participates in the displacement reaction, it can only produce +2 ferric salts.
8. When a metal element is put into a mixture of several salt solutions, the metal at the bottom of the metal activity order table is replaced first, and then the metal that is slightly lower is replaced in turn. Abbreviated as "In the order of metal activity, the distance is far, and the reaction is first".
9. Put several different metals into the same salt solution, and the reaction is similar to putting a metal element into a mixture of several salt solutions, which is also in the order of metal activity, the farther the reaction first, and then the farther the reaction.
10. The key points of blast furnace ironmaking.
The function of coke: one is to generate carbon monoxide, the reducing agent, and the other is to increase the temperature of the blast furnace;
The main function of limestone is to convert the silica in the ore into slag for removal;
The iron obtained by blast furnace ironmaking is pig iron, and its main component is iron, and it also contains elements such as C, P, and S.
11. Key points of laboratory simulation of industrial ironmaking:
Carbon monoxide reduces reddish-brown iron oxide to obtain a black powder, reducing iron powder, and the shape of iron varies according to color. In the process of reducing iron ore with carbon monoxide, special attention should be paid to the exhaustion of the air in the pipe before heating, and the exhaust gas must be treated before it can be discharged. Note that the heating instruments in the observation device are different, one is an alcohol lamp, the other is an alcohol blowtorch, and the reaction conditions for carbon monoxide to reduce iron ore are high temperatures.
12. Copper rust requires copper to be in contact with water, oxygen and carbon dioxide at the same time. Basic copper carbonate (Cu2(OH)2CO3) is generated
13. The essence of iron rust and iron combustion is oxidation reaction, but the violent oxidation reaction of iron combustion and iron rust is slow oxidation, and the reaction product rust is red, while ferric oxide is black.
14. Attention to metal corrosion.
The main component of rust is iron oxide, which is red in color, has a loose and porous structure, and is easy to absorb water, so if the rust on the surface of iron products is not removed in time, it will accelerate the speed of rust;
At high temperatures or in saltwater environments, iron also rusts faster. This is the reason why the water on the used kitchen knife or the iron pot after frying is not wiped clean, and it will rust overnight.
15. The common substitutes for metal materials in daily life include water pipes, sewer pipes, doors and windows, etc., which are changed from metal materials to plastic pipes or plastic aluminum pipes, plastic steel doors and windows. Plastic aluminum and plastic steel are special plastics, not metal materials.