1. Drop sodium hydroxide solution into copper sulfate solution and observe what happens to the solution.

2 NaOH+CuSO4 = Na2SO4+Cu (OH) 2 ↓ forms a blue flocculent precipitate.

2. Take 1 piece of copper sulfate crystal and heat it in a large test tube to observe the change of copper sulfate crystal.

Cuso 4·5H2O = cuso 4+5H2O blue solid turns white gradually.

3. After the experiment, put out the alcohol lamp, cool the big test tube, and then add water to the cooled white copper sulfate powder drop by drop to observe what will happen.

Cuso 4+5H2O = cuso 4·5H2O White solid turns blue gradually.

1-2 Exploring the Properties of Acids

A, the nature of hydrochloric acid:

Experimental exploration 1: 2 drops of purple litmus test solution were dropped into sodium hydroxide solution, and the solution was blue;

Then drop hydrochloric acid drop by drop. What is the color change of the solution?

From blue to purple, and finally to red.

Hydrochloric acid+sodium hydroxide = sodium chloride+H2O

Patients who think of hyperacidity often take a pill called "Weishuping" for treatment. The main component of tablets is aluminum hydroxide. Why can it be used to treat hyperacidity?

3 hydrochloric acid+aluminum hydroxide = aluminum trichloride+3H2O

Experimental exploration 2: a, put the egg shell into a test tube filled with hydrochloric acid, and put the burning match into the mouth of the test tube. What do you see? Bubbles are generated on the surface of the eggshell, and the burning wooden stick will go out when it goes in.

2HCl + CaCO3 = CaCl2 + H2O + CO2

B. Sodium carbonate reacts with hydrochloric acid to clarify the gas produced by limewater and observe the phenomenon?

2HCl + Na2CO3 = 2NaCl + H2O + CO2

Inspection of CO32-:Adding hydrochloric acid will produce gas (carbon dioxide), which will make the clear limewater turbid.

Calcium hydroxide+carbon dioxide = calcium carbonate ↓+H2O

Experimental exploration 3: a, add hydrochloric acid to the test tube containing rusty nails, shake it and observe the phenomenon later?

Rust disappears and the solution turns yellow.

6HCl + Fe2O3 = 2FeCl3+3H2O

B, add hydrochloric acid into a test tube containing a small amount of copper oxide powder, heat it slightly, and observe the phenomenon?

The black powder disappears and the solution turns blue.

2HCl + CuO = CuCl2 + H2O

Experimental Inquiry 4: A. Propose scenarios and questions.

Dilute hydrochloric acid can be used to remove rust. It can be observed that the rust gradually dissolves and the solution turns yellow. The chemical equation of this reaction is

Fe2O3+6HCl = 2FeCl3+3 H2O. However, it was later seen that bubbles formed on the surface of iron, but no gas was produced when iron oxide in rust reacted with dilute hydrochloric acid. So how did this gas come from? What is this? Is it caused by the reaction between iron and dilute hydrochloric acid?

B, your hypothesis is that metals such as iron can react with acids to produce gases.

C, design experiment:

D Experimental conclusion: Metals such as iron can react with dilute hydrochloric acid to produce gas, and the gas produced is hydrogen. It also shows that acidic solutions can react with many metals to produce hydrogen.

The chemical equation for the reaction of zinc and iron with dilute hydrochloric acid is:

Fe + 2HCl === FeCl2 + H2 ↑

Zn + 2HCl === ZnCl2 + H2↑

E. application:

1. Derusting: When using dilute hydrochloric acid for derusting, there should be neither too much acid nor too long, otherwise the dilute hydrochloric acid will continue to react with iron.

2. Hydrogen production: dilute hydrochloric acid or dilute sulfuric acid can be used to produce hydrogen in the laboratory.

Second, dilute sulfuric acid acidity experiment:

[Experiment 1]: Drop dilute sulfuric acid into a test tube filled with zinc and observe the phenomenon.

Phenomenon: A large number of bubbles are generated on the surface of zinc particles.

Chemical equation: zinc+sulfuric acid = = zinc sulfate +H2 =

[Experiment 2]: Drop dilute sulfuric acid into a test tube filled with copper oxide and observe the phenomenon.

Phenomenon: Black copper oxide dissolves and disappears, and the solution turns blue.

Chemical equation: CuO+H2SO4 = CuSO4+H2O.

[Experiment 3] Dilute sulfuric acid was dropped into a test tube filled with copper hydroxide to observe the phenomenon.

Phenomenon: blue copper hydroxide dissolves and the solution turns blue.

Chemical equation: copper hydroxide+sulfuric acid = copper sulfate+H2O.

[Experiment 4]: Dilute sulfuric acid was dropped into the solution containing colorless barium chloride to observe the phenomenon.

Phenomenon: white precipitate is produced.

Chemical equation: BaCl2+H2SO4 = BaSO4 ↓+2HCl.

SO42: White precipitate appears when barium nitrate solution is added dropwise, but it does not dissolve when dilute nitric acid is added dropwise.

When testing Cl- and SO42, a few drops of dilute nitric acid should be added to eliminate the interference of impurity ions such as CO32. Because CO32—- comes into contact with AgNO3 or BaCl2 solution, white precipitates Ag2CO3 and BaCO3 will also be formed, but these precipitates are dissolved in dilute nitric acid. such as

BaCO3+2HNO3=Ba(NO3)2+CO2↑+H2O

Ag2CO3+2HNO3=2AgNO3+CO2↑+H2O

AgCl and BaSO4 are insoluble in dilute nitric acid, so it is necessary to add some dilute nitric acid during inspection. If the white precipitate is insoluble, it can be confirmed that there is Cl- or SO4-.

When both Cl- and SO42-may exist in the solution, which ion should be tested first?

SO42-should be tested first, and Ba(NO3)2 solution and dilute nitric acid should be used as reagents instead of BaCl2 solution and hydrochloric acid. It is necessary to filter out BaSO4 _ 4 precipitate, and then add AgNO3 _ 3 solution and dilute nitric acid to the filtrate to test Cl-. Because silver sulfate is slightly soluble in water, if the concentration of so42- in the solution is high, Ag2SO4 (slightly soluble) precipitate will be generated when AgNO3 solution is added to detect Cl- first, which will interfere with the detection of Cl-.

* * * The nature of acid.

(1), acid can make purple litmus turn red, colorless phenolphthalein does not change color.

② Acid+metal = salt+hydrogen.

③ Acid+metal oxide = salt+water

④ Acid+alkali = salt+water

(5), acid+salt = new salt+new acid

1-3 to explore the properties of alkali

First, the nature of alkali

1. Alkali can react with acid-base indicator.

[Experiment 1] Purple litmus test solution and colorless phenolphthalein test solution were dropped into four test tubes filled with sodium hydroxide solution and clear limewater respectively, and the color changes of the solutions were observed. Take two PH test strips and put them into two test tubes respectively, then drop sodium hydroxide solution and clarified lime water into the test tubes respectively, observe the color change and fill in the following table.

Conclusion: Alkaline solution can turn purple litmus test solution blue and colorless phenolphthalein red.

Thinking: Why is it called "alkali solution" here instead of "alkali" directly?

Because some alkalis are insoluble in water, such as copper hydroxide and iron hydroxide, the purple litmus test solution and colorless phenolphthalein test solution cannot be discolored because they are insoluble in water.

2. Alkali can react with acid.

[Experiment 2] Sodium hydroxide solution reacts with acid.

1), in two test tubes with a small amount of dilute sodium hydroxide solution, drop 1 drop phenolphthalein test solution into each test tube, and the solution turns (red). Drop dilute hydrochloric acid and dilute sulfuric acid into two test tubes respectively, and shake while dropping until (red) just disappears.

This shows that what has happened to the acidity and alkalinity of the solution? Become neutral

2) Absorb the reacted solution with a dropper and drop it into an evaporating dish, and dry it with low fire. What's left on the evaporating dish?

White crystal.

Chemical equation: sodium hydroxide+hydrochloric acid = sodium chloride +H2O.

2NaOH + H2SO4 = Na2SO4 + 2H2O

Neutralization reaction:

1) Definition: The reaction between alkali and acid to produce salt and water is called neutralization reaction.

2). Application of neutralization reaction:

In agriculture, hydrated lime [Ca(OH)2] is used to reduce the acidity of soil and improve acidic soil. In petroleum industry, sodium hydroxide [NaOH] is used to neutralize excess sulfuric acid [H2SO4]. Medical use of aluminum hydroxide [Al(OH)3] to neutralize excessive gastric acid.

3) Nature of neutralization reaction:

Essentially, H+ ionized by acid and OH- ionized by alkali combine to form neutral water.

3. Alkali reacts with nonmetallic oxides.

[Experiment]: Introduce carbon dioxide into a test tube filled with clear limewater and observe what happens:

Clear limewater becomes turbid.

Chemical reaction equation: CO2+Ca(OH)2 = CaCO3↓+ H2O.

This reaction is usually used to test the presence of carbon dioxide.

Thinking:

1). If you want to absorb or remove carbon dioxide, you can use sodium hydroxide solution, but how to write its reaction equation?

Carbon dioxide +2 sodium hydroxide = sodium carbonate +H2O

2). What is the harm of sulfur dioxide discharged into the atmosphere?

It will pollute the atmosphere, and the waste gas discharged by sulfuric acid industry contains sulfur dioxide gas.

How to remove sulfur dioxide gas?

Sodium hydroxide solution is commonly used in industry to absorb sulfur dioxide.

SO2 + 2NaOH = Na2SO3+ H2O

Alkali liquor is commonly used in industry to absorb toxic acid gases, such as H2S, SO2 and HCl.

Thinking:

1), why can't reagent bottle with sodium hydroxide solution use a glass stopper? Instead, use rubber plugs or wooden plugs.

Silicon dioxide +2 sodium hydroxide = sodium silicate +H2O

2) Where sodium hydroxide or sodium hydroxide solution can't be opened, why?

Carbon dioxide +2 sodium hydroxide = sodium carbonate +H2O

4. Alkali can react with some salts.

[Experiment]: 1. 2-3 ml of CuCl2 _ 2 solution and FeCl3 _ 3 solution were injected into two test tubes respectively. What color do they show? Copper chloride is blue-green and iron chloride is yellow.

2. Dropping 1ml NaOH solution into the above two test tubes respectively, what happened in the test tubes?

Phenomenon: blue flocculent precipitation appears in the test tube containing copper chloride solution;

Chemical reaction equation: CuCl2+2NaOH = Cu(OH)2↓+2NaCl.

Red-brown flocculent precipitation appeared in the test tube containing ferric chloride solution.

Chemical reaction equation: FeCl3+3NaOH = Fe(OH)3↓+3NaCl.

Universality of alkali

Alkaline substances can turn purple litmus blue and colorless phenolphthalein red.

2) Alkali reacts with acid to produce salt and water, which is also called neutralization reaction.

3) The nonmetallic oxide reacts with alkali to generate salt and water.

4) Salt and alkali react to form another alkali and another salt.

What should we pay attention to the chemical properties of the above alkali?

(1) Only soluble alkali can meet the above four properties, and insoluble alkali can only meet the second one.

(2) Article 4 The salts and bases involved in the reaction must be soluble.

Second, the personality of alkali:

(1) Common name of sodium hydroxide (chemical formula: NaOH): caustic soda, caustic soda, caustic soda.

【 Experiment 1】:① Read the reagent bottle label of sodium hydroxide.

Take out a small piece of NaOH solid with tweezers and put it on the surface mirror.

② Ask students to observe the color, state and surface dryness of NaOH just taken out. What happened to the surface state after a few minutes? White solid, which can absorb moisture in the air and deliquesce.

When a substance is exposed to the air, it absorbs the moisture in the air, and the surface is moist and gradually dissolves, which is called deliquescence.

It can be seen that sodium hydroxide solid can also be used as a desiccant for some gases (such as hydrogen and oxygen).

Through the above experiments and analysis, can we get any personality of sodium hydroxide?

③ Move NaOH in the glass dish into the test tube, add a small amount of water (about 3 ml), touch the bottom of the test tube with your hand, and pay attention to the temperature change. It is very soluble in water and releases a lot of heat when dissolved.

④ 1) Dip a small amount of solution with a glass rod.

2) Put the obtained solution on paper, and what will be observed after a while? It is highly corrosive.

⑤ Put a pinch of rabbit hair into a test tube filled with caustic soda solution, and observe the phenomenon after heating and boiling:

Rabbit hair is soluble, and wool is easily hydrolyzed under alkaline conditions, that is, it is not alkali-resistant.

Sodium hydroxide personality:

① NaOH is a white solid,

(2) NaOH is easily deliquescent in air.

③ Soluble in water, releasing a lot of heat when dissolved.

(4) It is highly corrosive and can dissolve organic matter, so it must be used with great care.

⑤ The aqueous solution of alkali has a satiny feeling.

Thinking:

1. How should sodium hydroxide be preserved in the laboratory? Why?

Laboratory sodium hydroxide solid must be sealed and preserved, because sodium hydroxide is exposed to air, which is not only easy to absorb moisture in the air and deliquescent, but also easy to react with carbon dioxide in the air and deteriorate.

2. Sodium hydroxide is deliquescent easily. What do you think should be used in this respect? And what should be paid attention to when using it?

According to the deliquescent nature of sodium hydroxide, sodium hydroxide is often used as a desiccant in the laboratory. But it can't dry acid gases, such as carbon dioxide, sulfur dioxide, H2S and hydrogen chloride.

(2) Calcium hydroxide: [chemical formula: Ca(OH)2] Common name: slaked lime, slaked lime, lime slurry and lime milk.

[Experiment 2]: (1), drop hydrochloric acid and dilute sulfuric acid solution into calcium hydroxide solution and observe what happens.

Calcium hydroxide+dihydrochloride = calcium chloride+dihydrate

Calcium hydroxide+sulfuric acid = calcium sulfate +2H2O

(2) What happens when calcium hydroxide solution drops into sodium carbonate solution and ferric chloride solution?

White precipitate and reddish-brown precipitate were produced.

Chemical reaction equation: Ca(OH )2+Na2CO3 = CaCO3 ↓+2NaOH.

3Ca(OH)2+2 FeCl 3 = 2Fe(OH)3↓+3c ACL 2

Calcium hydroxide personality:

1)Ca(OH)2 is a white powdery solid, slightly soluble in water, and its aqueous solution is commonly known as limewater.

2) Ca(OH)2 is also corrosive.

3) Ca(OH)2 is alkaline.

1-4 Several Important Salts

1. What is salt?

① Salt is a compound that can produce metal cation (or ammonium ion) and acid anion when ionized.

② Salt is the product of acid-base neutralization. The acid ions in the acid combine with the metal (or ammonium) ions in the alkali.

(3) Besides various colors, salt crystals have regular geometric shapes.

Second, the properties of several salts

① sodium carbonate crystal (Na2CO3 10H2O)

1. At room temperature, crystals are easily weathered when exposed to air, and lose crystallization water to become white powder of sodium carbonate (chemical formula: Na2CO3), commonly known as soda ash or soda ash.

A substance containing a certain amount of water molecules is called crystalline hydrate.

2, sodium carbonate and acid-base indicator reaction

[Experiment]: Dropping phenolphthalein reagent into sodium carbonate solution, what did you find? The solution turns red

It can be seen that sodium carbonate aqueous solution is alkaline.

3. Reaction with acid:

Sodium carbonate+sulfuric acid = sodium sulfate +H2O+ carbon dioxide

4. Reaction with alkali:

Na2CO3+Ca (OH) 2 = CaCO3 ↓+2 NaOH (used to make caustic soda)

Application:

Sodium carbonate can be used to make glass, soap and detergent, and its alkalinity can be used in textile industry.

Test method of CO32-: Drop hydrochloric acid into the mixture. If gas is generated, and the gas can make the clear limewater turbid, it means that the compound contains CO32-.

② Calcium carbonate (CaCO3)

Calcium carbonate is an important building material.

1, white and pure calcium carbonate rock is called white marble.

2. Calcium carbonate with patterns due to impurities is called marble.

3. Dense calcium carbonate rock is called limestone.

Calcium carbonate is an insoluble salt.

1, the reaction of calcium carbonate with acid

Calcium carbonate+hydrochloric acid = calcium chloride +H2O+ carbon dioxide

high-temperature

2. High temperature decomposition of calcium carbonate

CaCO3= H2O+CO2

Usage: 1 Calcium carbonate is an important building material (stone pillar or handicraft).

2. The main use of limestone is to produce cement.

Thinking: How to prove that a rock is carbonate?

Take a small piece of rock and drop hydrochloric acid to observe whether there are bubbles; If bubbles are constantly generated, carbonate will exist in the rock.

③ Salt (NaCl) is a white solid and easily soluble in water.

Source: mainly from seawater drying and well water salt making.

The purification method of crude salt: dissolution-filtration-evaporation crystallization.

Usage: 1 Salt is not only an indispensable food for human beings, but also an important chemical raw material.

2, can make sodium hydroxide, chlorine, hydrochloric acid, etc.

Preparation of physiological saline (0.9%)

The concentration of sodium ion in 0.9% sodium chloride solution is almost equal to that in human plasma, so it is called physiological saline.

Thinking: Salt water is often used to clean wounds in daily life. Do you know why?

Because the concentrated salt solution can make the water in the cell seep out, make protein coagulate, and it has bactericidal effect.

Characteristics of salt:

1, acid+salt → new acid+new salt

2, alkali+salt → new alkali+new salt

3. Salt+Salt → New Salt+New Salt

Some salts will decompose when heated.

Third, the preparation of salt:

[Experiment]: Add calcium chloride solution into a test tube filled with sodium carbonate solution and observe the experimental phenomenon?

Sodium carbonate+calcium chloride = calcium carbonate ↓+sodium chloride

Possible methods of making salt

1, metal+acid-salt+hydrogen 2, acid+metal oxide-salt+water.

3. Acid+alkali-salt+water 4. Alkali+nonmetallic oxide-salt+water

5, metal+salt-new metal+new salt 6, acid+salt → new acid+new salt

7, alkali+salt → new alkali+new salt 8, salt+salt → new salt+new salt

Double decomposition reaction: A reaction in which new compounds are formed because compounds exchange components with each other.

The conditions of displacement reaction are as follows:

1. One of precipitation, gas and water is produced in the product.

2. The reaction without acid requires that all reactants must be soluble. (Insoluble in acid)

Solubility formula

Potassium nitrate, sodium nitrate and ammonium nitrate are soluble, but silver chloride is insoluble.

In addition to sulfate, insoluble barium sulfate.

Phosphate carbonate, only soluble in potassium, sodium and ammonium.

Finally, alkali only dissolves potassium, sodium, ammonium, calcium and barium.

IV. Salt and fertilizer

1, chemical fertilizer is a kind of fertilizer (referred to as chemical fertilizer) made of minerals, air, water and other raw materials through chemical processing.

2. Fertilizer type: nitrogen fertilizer: nitrogen-containing nitrogen fertilizer.

Phosphate fertilizer: It contains phosphorus and is called phosphate fertilizer.

Potash fertilizer: it is called potash fertilizer.

3. Compound fertilizer: Fertilizer containing two or more main nutrients is called compound fertilizer.

4. Nitrogen fertilizer: mainly ammonium salts, including nitrate and urea. It can promote the growth of crop stems and leaves and contains important elements that constitute chlorophyll.

Commonly used nitrogen fertilizer: it is nitrogen-containing organic matter, that is, human urine. Fertilizer: urea and carbon dioxide

Preparation: the acid reacts with ammonia to obtain the product.

Ammonia and carbonic acid: NH3+H2O+CO2 = NH4CO3

Ammonia and sulfuric acid: 2nh3+H2SO4 = (NH4) 2SO4

In the composition of salt, the cations contained are not necessarily all metal cations, but also complex cations (charged atomic groups).

[Experiment1]:1. What happens when sodium hydroxide solution drops into concentrated ammonium sulfate solution?

(NH4)2so 4+2 NaOH = na2so 4+2H2O+2nh 3↑

[Experiment 2]: Put the wet red litmus test paper on the mouth of the test tube. Does the color of the test paper change?

Turn the wet red litmus test paper into blue

What is the reason for the change? The ammonia gas produced in the product is alkaline.

It is concluded that when ammonium salt reacts with alkali (soluble alkali), ammonia gas which can turn wet red litmus paper blue is released. This method is used for the inspection of ammonium salts.

Ammonium ion test:

Drop sodium hydroxide solution into the solution. If gas is generated and the gas can turn red litmus paper blue, it means that the original solution contains ammonium ions.

The role of phosphate fertilizer: promote the development of crop root system, enhance the ability of absorbing nutrients and resisting cold and drought, and promote the increase of crop spike number and full grain.

The role of potassium fertilizer: to promote the vigorous growth of crops, stout stems, enhance the ability to resist pests and diseases, and promote the production of sugar and starch.

Note: Long-term use will cause soil hardening and destroy soil structure. Therefore, it is necessary to apply some farm manure (organic fertilizer) which is beneficial to good soil structure and improve soil fertility.

1-5 looking for the law of metal change

I. Chemical properties of metals

(1) The reaction of metal with oxygen.

[Experiment 1]: Put magnesium tape and copper wire on the outer flame of alcohol lamp and heat it at the same time. It was pointed out that:

Silver-white magnesium belt burns rapidly, gives off dazzling light, and releases a lot of heat to generate white solid; red

Copper wire will not burn, but the surface will turn black.

light

2Cu +O2 = 2CuO

2 mg+oxygen = 2 mg oxygen

[Experiment 2]: The unburned copper wire was inserted into a test tube filled with hydrochloric acid, and the solution turned blue.

CuO +2HCl = CuCl2 + H2O

In humid air, metallic iron will be oxidized by oxygen in the air to form rust. (The main component is Fe2O3)

【 Conclusion 】 Some metals can burn in air, such as magnesium.

Some metals can burn in pure oxygen, such as iron;

Although some can't burn, they will react to generate oxides, such as copper, iron and aluminum, which can generate copper oxide, iron oxide and aluminum oxide respectively.

Alumina is a dense protective film.

② the reaction between metal and acid.

Put the aluminum sheet into a test tube filled with dilute hydrochloric acid, and observe and record this phenomenon:

[Experiment1]:1. Put a small amount of magnesium strips, zinc particles and copper sheets into three test tubes filled with dilute hydrochloric acid, and observe:

There are bubbles on the surface of magnesium strips and zinc particles, but there are no bubbles on copper sheets.

2. When the mouth of the test tube producing gas is ignited, it will make a crackling sound, indicating that hydrogen is produced.

The chemical equation of this reaction is: Mg+ 2HCl = MgCl2+H2↑.

Zn+ 2HCl = ZnCl2+ H2↑

3. Put a small amount of magnesium rods, zinc particles and copper sheets into three test tubes filled with dilute sulfuric acid respectively, and observe the phenomenon:

Bubbles are generated on the surfaces of magnesium strips and zinc particles. Copper sheets do not produce gas.

The chemical equation of the reaction is Mg+ H2SO4 = MgSO4+H2↑.

Zinc+sulfuric acid = zinc sulfate+H2

[Conclusion] Aluminum, magnesium, iron, zinc and other metals can react with dilute sulfuric acid and dilute hydrochloric acid to generate hydrogen, while copper cannot react with dilute sulfuric acid and dilute hydrochloric acid.

Thinking 1: What should I pay attention to when using aluminum containers?

Do not contain acidic or alkaline substances, or the container will be corroded.

Thinking 2: Are all metals corroded by acid?

No, the metal behind hydrogen in the metal activity sequence table cannot react with the calculation solution.

(3) The reaction of metals with some salt solutions.

[Experiment 2] 1. Immerse a clean iron wire into a test tube containing copper sulfate solution, take it out after a while, and observe what has happened: a layer of red substance has formed on the surface of the iron wire.

The chemical reaction equation is: Fe+CuSO4 = FeSO4+Cu.

2. In the test tube containing ferrous sulfate solution, put a piece of clean copper wire, take it out later, and observe:

The surface of the copper wire has not changed. Description: There is no chemical change between copper and ferrous sulfate solution.

3. Immerse a clean copper wire into a test tube filled with silver nitrate solution and zinc sulfate, then take it out and observe.

A layer of silver white material was formed on the surface of copper wire immersed in silver nitrate solution, while copper wire immersed in zinc sulfate solution did not change.

The chemical equation of the reaction is: Cu+2AgNO3 = Cu(NO3)2+2Ag.

Thinking: according to the above experimental facts, the activity order of copper, silver and zinc is Zn >；; Cu & gtAg .

Second, the metal activity sequence:

Potassium calcium sodium magnesium aluminum zinc iron tin lead [hydrogen] copper mercury silver platinum

The metal activity gradually decreases from strong to weak.

Application law of metal activity sequence;

① Reaction between metal and acid: In the metal active sequence, only the metal before hydrogen can replace the hydrogen in the acid.

② Reaction between metal and salt solution: In the sequence of metal activity, only one metal with strong activity can replace another metal with weak activity from its salt solution.

4. Electron transfer in chemical reactions

The reaction of electron transfer between reactants is called redox reaction.

Displacement reactions are all redox reactions.

Copper hydrometallurgy: Fe+CuSO4 = FeSO4+Cu.

[Experiment] It is known that the active metal at the top of the metal active sequence table can react with water to generate alkali and hydrogen.

Please write down the chemical equations of the following reactions and speculate on possible experimental phenomena.

① Put a piece of metallic sodium the size of mung bean into a 1 small glass of water dripping with phenolphthalein.

Gas is produced, and the water dripping with phenolphthalein is red.

2Na+2H2O=2NaOH+H2 ↑

② Put a piece of metallic potassium as big as mung bean into a 1 small cup dripping with copper sulfate.

Gas is generated, and copper sulfate solution reacts with KOH solution to generate blue copper hydroxide precipitate.

2K+2H2O=2KOH+H2 ↑

2KOH+CuSO4 = K2SO4+Cu(OH)2↓

Existence and change of 1-6 organic matter

First of all, some simple organic matter

1. The concept of organic matter.

(1) Generally, carbon-containing compounds are called organic compounds, referred to as organics for short.

Corresponding to organic matter is inorganic matter, which includes simple substance and inorganic compound.

(2) Carbon oxides, carbonic acids and carbonates are carbon-containing compounds, but they are usually classified as inorganic compounds because they are similar to inorganic compounds in structure, composition and properties.

(3) Most organic substances contain elements such as carbon, hydrogen, oxygen and nitrogen.

2. Methane

(1) The chemical formula of methane is CH4, which is the simplest organic matter.

Straw and animal manure will also produce a lot of biogas after fermentation, which is often used as heating fuel in rural areas.

(2) Methane is the main component of biogas, natural gas and liquefied petroleum gas. A large amount of methane has also been found in the atmosphere of Mars.

[Experiment]: Combustibility of methane

Ignite methane gas, cover the inner wall above the flame with a beaker filled with lime water, and observe the phenomenon:

Blue flame is produced, and lime water becomes turbid at the same time.

The chemical equation is CH4+2o2 = = CO2+2h2o.

Because methane gas is easy to explode when mixed with air or oxygen, it needs to be purified before use. Pay attention to safety when using biogas or natural gas as fuel at home.

3. In addition to methane,

Butane (C4H 10) is the main component of liquid in lighters, which is easy to liquefy and flammable.

The chemical equation of its combustion in air is 2c4h10+13o2 = = 8co2+10h2o.

(2) Acetylene C2H2, flammable, can generate high temperature above 3000 degrees when burning, and can be used for welding and cutting metals.

The chemical equation of combustion in air is 2c2h2+5o2 = = 4co2+2h2o.

4. Characteristics of organic matter.

(1) Most organic compounds are low in melting point, volatile, nonconductive and easy to burn.

(2) Many organic substances, such as alcohol, ether and benzene, are common good solvents.

5. Use of organic matter.

(1) methane is a common clean fuel.

(2) Acetylene combustion flame is used for cutting or welding metal.

(3) Ethylene is an important chemical raw material.

(4) Alcohol is used for disinfection and fuel.

(5) Acetic acid is used as vinegar.

Second, organic matter that is of great significance to life activities.

1. Organic matter is the main component of organism tissues. The growth and development of human body and the metabolism of various tissues in the body all need the participation of various organic substances.

2. The most basic organic substances in human body are sugar, protein, fat, etc.

(1) Sugar is the main source of energy consumed by human body, and it is also the raw material for synthesizing many important compounds in human body. Common sugars are glucose (monosaccharide), fructose, sucrose, maltose and lactose, and the simplest sugar is glucose (C6H 12O6).

(2) protein is the basic substance of organism, and protein is the most complex and changeable macromolecule in cell structure. The relative molecular weight is about 1.2 ~ 1 ten thousand. Protein consists of four elements: carbon, hydrogen, oxygen and nitrogen.

1. Burning nails, hair or wool can smell burnt feathers and see black smoke at the same time.

2. Light the cotton fiber and you can smell the burnt cotton cloth.

Thinking about igniting cotton fiber and wool, why do they smell different?

The main component of cotton is cellulose, and the main component of wool is protein.

(3) Fat: It is composed of three elements: carbon, hydrogen and oxygen. A part of the ingested fat is converted into energy needed for life activities through oxidation, and the other part exists in the body in the form of stored energy (subcutaneous fat).

Most of the food people eat every day is organic. These organic substances are digested, absorbed and stored in life activities.

The process of transformation and consumption is constantly changing, realizing the transformation of various substances and the transfer of energy.

4. The basic way of material circulation in nature.

(1) Various inorganic substances in nature are absorbed by plants and enter the biosphere from the natural environment to become organic substances.

(2) Transfer through the food relationship between organisms. Organisms transform organic matter into inorganic matter through breathing, and organic matter into inorganic matter through the decomposition of biological excreta and corpses, returning to the natural environment.