Important compounds of aluminum teaching plan

Teaching plan writing is an essential link in teacher recruitment interview. But for most candidates, how to write the lesson plan is not particularly clear. The following is the teaching plan of "Important Compounds of Aluminum" that I compiled for you. Welcome to read, for reference only, I hope it will help you.

Teaching plan of important compounds of aluminum (I) I. Teaching objectives

Knowledge and skills

Can tell the main physical properties of alumina; Learn the method of preparing aluminum hydroxide in the laboratory; Understand the concepts of amphoteric oxide and amphoteric hydroxide, and write the chemical equations and ionic equation of the reaction of Al2O3 and Al(OH)3 with acid and alkali respectively.

Process and method

By designing experiments to judge amphoteric compounds and verify their properties, we can learn scientific experimental methods, correct experimental operations, reasonable experimental design and analysis, and improve the ability of comprehensively using experimental methods to solve problems.

Emotional attitudes and values

Analyze the transformation relationship between aluminum compounds and learn to look at things dialectically.

Second, the difficulties in teaching

focus

Amphoteric properties of alumina and aluminum hydroxide: preparation of aluminum hydroxide.

difficulty

Preparation of aluminum hydroxide: the formation of amphoteric oxide and amphoteric hydroxide concepts.

Third, the teaching process

Link 1: Introducing a new lesson

Teachers' activities review the experimental phenomenon of aluminum foil melting by heating. Molten aluminum doesn't drip, just like it is covered with a film. What film is this? Why doesn't molten aluminum drip?

Students answer alumina; Alumina, which constitutes the film, has a higher melting point than aluminum and is wrapped around aluminum, so molten liquid aluminum will not drip.

In fact, the reason why aluminum products are widely used in our lives is because of the protective effect of alumina. What other properties does alumina have besides the above properties? Besides alumina, the important compound of aluminum is aluminum hydroxide. What are the properties of aluminum hydroxide? Let's study together in this class.

Link 2: New Curriculum Teaching

1, alumina

Physical properties of (1) alumina

The teacher's activities showed pictures of refractory materials made of alumina, such as refractory crucible, refractory tube and ball bearing, as well as information about the physical properties of alumina. Question: What are the physical properties of alumina, combined with the experiment of heating and melting aluminum foil and the pictures of refractories made of alumina above?

Students answer that alumina is a white solid, insoluble in water, with high melting point and high strength.

(2) Chemical properties of alumina

The teacher asked how to remove this oxide film on the aluminum surface.

According to the properties of aluminum, alumina can react with both acid and alkali. Therefore, this oxide film can be removed with acid or alkali.

Teachers provide experimental equipment (instruments and medicines: test tubes, rubber droppers, keys, HCl solution, NaOH solution, alumina powder) to guide students to carry out experiments.

The students in the two experimental groups conducted experiments separately and reported according to the phenomenon. Phenomenon: Alumina can be dissolved in both acid and alkali.

Please write the chemical reaction equation and ion reaction equation of aluminum oxide reacting with HCl and NaOH respectively according to the equation of aluminum reacting with HCl and NaOH respectively.

Students write chemical equations: Al2O3+6HCl=2AlCl3+3H2O, Al2O3+2NaOH = 2NALO2+H2O.

Ionic equation: Al2O3+6H+=2Al3++3H2O, Al2O3+2OH-=2AlO2-+H2O.

The teacher summed up the above experiments and showed that alumina has the properties of both acidic oxide and alkaline oxide. The oxide that can react with acid and alkali to form salt and water is called amphoteric oxide, so alumina is amphoteric oxide.

2. Aluminum hydroxide

The teacher asked, sodium hydroxide can be generated by the reaction between sodium oxide and water, so how to prepare aluminum hydroxide? Can the reaction between alumina and water be used? If not, what can be done?

The student answered no; Aluminum salts can be used to react with alkali.

Teacher activity demonstration experiment 3-7, what is the white colloidal substance obtained by the reaction? How to write the reaction equation?

Students answer aluminum hydroxide; Al2(SO4)3+6nh 3·H2O = 2Al(OH)3↓+3(NH4)2so 4

The teacher asked questions and summarized the physical properties and uses of aluminum hydroxide: aluminum hydroxide is a white colloidal substance, which is almost insoluble in water, but it can condense suspended solids in water and adsorb pigments. In the laboratory, aluminum hydroxide is often prepared by the reaction of aluminum salt solution with ammonia water. In addition, both aluminum and alumina can react with acid and alkali. Can aluminum hydroxide also react with acid and alkali?

Student 1 the answer is yes.

Student 2' s answer is uncertain.

Teachers' activities show the demonstration video of the reaction of aluminum hydroxide with dilute hydrochloric acid and sodium hydroxide solution, and guide students to summarize the experimental phenomena.

Students observe phenomena and record activities, and try to write reaction equations.

The teacher summarized the chemical equation and ionic equation of the reaction of Al(OH)3 with dilute hydrochloric acid and sodium hydroxide solution.

Al(OH)3+3 HCl = ALC L3+3H2O Al(OH)3+3H+= Al3 ++ 3H2O

Al(OH)3+NaOH = NAA lo 2+2H2O Al(OH)3+OH-= alo 2-+2H2O

The teacher added that according to the above, we know that alumina is an amphoteric oxide, and Al(OH)3 can react with both acid and alkali, so it is an amphoteric hydroxide.

The teacher asked why ammonia often reacts with aluminum sulfate solution to prepare aluminum hydroxide instead of sodium hydroxide solution.

The students answered that sodium hydroxide is a strong base, which can react with aluminum hydroxide to generate sodium metaaluminate, while ammonia water is a weak base and cannot continue to react with aluminum hydroxide.

The teacher emphasized that although aluminum hydroxide can react with alkali, it can only react with strong alkali.

Al(OH)3 supplemented by teachers is unstable, and it is decomposed by heating to produce alumina and water.

Generally speaking, insoluble bases such as Fe(OH)3 and Cu(OH)2 can be decomposed into oxides and water under heating conditions.

Link 3: Consolidate and improve

The teacher asked the students to explain why Weishuping can relieve stomachache.

The students replied that Al(OH)3 is one of the medical gastric acid neutralizers. It is alkaline but not enough to cause strong irritation or corrosion to the stomach wall, but it can react with acid to neutralize excessive gastric acid. In addition, Al(OH)3 is insoluble in water and is a gelatinous substance, so it can protect the ulcer surface and has a lasting effect.

Step 4: Summarize the homework.

Class Summary This class learned the gender of aluminum oxide and aluminum hydroxide through experiments, mastered the laboratory preparation method of aluminum hydroxide, and understood the use of Al(OH)3.

Homework combines today's knowledge to look up the materials for preparing aluminum from bauxite, and report the experimental principle in the next class.

Fourth, blackboard design.

Teaching plan of important compounds of aluminum (II) Ⅰ. teaching material analysis

The important compound of aluminum is the content of the second lesson of the second section of the third chapter of compulsory chemistry in senior high school of People's Education Press. The third chapter is about the knowledge of elemental compounds. Elemental compounds are the basic knowledge of middle school chemistry, and also the basic knowledge that students often need to contact, understand and apply in their future work and life. This knowledge can not only supplement the perceptual knowledge materials for the previous experiments and theoretical knowledge, but also help students gradually master some basic methods of learning chemistry; It can also make students really understand the important role of chemistry in promoting social development and improving human living conditions.

The third chapter, Metals and Their Compounds, is a vivid embodiment of the concept of "Chemistry is an experiment-based subject" in the first chapter, and is a concrete application of the knowledge of material classification, ion reaction and redox reaction in the second chapter, which lays a solid foundation for the theory of material structure, periodic table of elements, chemical reaction and energy in the second compulsory course and plays a connecting role in the whole teaching material structure system.

In this category, the important compounds of aluminum are abundant in nature, widely used and unique in nature, occupying an irreplaceable important position. Learning this part of knowledge requires the help of colorful chemical experiments, which will enhance students' interest in learning chemistry.

At the same time, learning this section well can help students solve many practical problems in life.

Second, the analysis of learning situation

Students have learned the simple substance of aluminum and the important compounds of sodium before, and have known the aluminum-containing compounds such as aluminum salt and metaaluminate, and have some experience in the study of metal compounds, which laid the foundation for the study of this course. However, most students need to deepen their understanding of the properties and learning methods of metal compounds, especially the knowledge of learning elemental compounds through experimental inquiry, which may not be proficient for most students. Therefore, the teaching of this course is to make full use of students' existing knowledge and experience, and guide students to explore the preparation method of aluminum hydroxide by controlling the variables in the experiment, and gain a gender understanding of aluminum hydroxide from it.

Third, the design ideas

Part I: Alumina

Create problem scenarios → analyze and discuss → solve problems → summarize and sort out.

Part II: Aluminum hydroxide

Introduction of questions → theoretical analysis → experimental verification → conclusion.

Fourth, teaching objectives.

Knowledge and skills:

1, can tell the main physical properties of alumina and aluminum hydroxide;

2. Understand the laboratory preparation principle and operation of aluminum hydroxide;

3. Understand the amphoteric nature of aluminum oxide and aluminum hydroxide, master the nature of decomposition of aluminum hydroxide by heating, and master the chemical equations and ionic equation of their reactions with hydrochloric acid and sodium hydroxide solution respectively.

Process and method

1, through the experiment, know the properties of aluminum hydroxide, and master the preparation method and experimental operation of aluminum hydroxide.

2. Cultivate students' observation ability, train students' logical thinking ability through comparative understanding of things and comprehensive analysis, and improve their innovative thinking ability.

Emotions, attitudes and values:

1. By teaching the properties and uses of Al2O3 and Al(OH)3, students' enthusiasm for learning chemistry is stimulated.

2. By exploring the gender of Al2O3 and Al(OH)3, students' thinking ability and comprehensive analysis ability are cultivated.

V. Teaching Emphasis and Difficulties

Key points: Amphoteric characteristics of alumina and aluminum hydroxide.

Difficulties: preparation and sexual exploration of aluminum hydroxide

Sixth, teaching methods.

Question guidance, experimental inquiry and practical feedback.

Seven, teaching supplies

Reagents: Al2(SO4)3 solution, ammonia water, NaOH solution and HCl solution.

Instruments: several test tubes, rubber droppers.

Eight, the teaching process

Introduce the teacher to show a group of pictures and guide the students to find out the similarities and differences of material components in the pictures: they are all aluminum-containing compounds. Then the task of this lesson is to study two important compounds of aluminum-alumina and aluminum hydroxide.

(A) the nature and use of alumina

Teachers' activities create problem situations;

Question 1: aluminum is an active metal. Why can aluminum products exist stably in the air?

Question 2: Aluminum can react with boiled water, but why can aluminum pot be used to boil water?

Question 3: When heating aluminum foil, why doesn't the melted aluminum foil drip down?

Question 4: There is alumina in the wear-resistant layers such as composite wood floor, mobile phone shell and computer shell, and there is alumina in the ball bearing. Ruby and sapphire are also important components of alumina, which shows the hardness of alumina.

Students read the textbook independently, think about and complete the above problems.

The physical properties and uses of Al2O3 are summarized: water-insoluble white solid, high hardness (ball bearing) and high melting point (refractory).

Teachers' activities present information: Scientists have found that Alzheimer's disease is closely related to aluminum intake. At the same time, aluminum is harmful to human brain, heart, liver and kidney functions. Therefore, the World Health Organization officially designated aluminum as a food pollutant in 1989 and controlled it. It is suggested that the daily intake of aluminum for adults should not exceed 60 mg. If you often eat fried foods such as fried dough sticks, oil cakes and noodles, drink canned drinks made of aluminum cans and eat acidic or alkaline foods cooked with aluminum tableware, the intake of aluminum will increase, thus affecting the function of brain cells, leading to memory loss, mental retardation and the risk of Alzheimer's disease.

Question: Why does eating acidic or alkaline food cooked with aluminum tableware often increase aluminum intake?

Students discuss the activities and guess that alumina may react with both acid and alkali.

Teachers' activities According to the properties of aluminum, let students recall which experimental phenomena can fully explain that alumina can react with acid and alkali.

Review of students' activity knowledge: put the aluminum foil that has not been sanded into hydrochloric acid and sodium hydroxide solution respectively, and no bubbles will be generated at first, but all bubbles will be generated after a while.

According to the reaction of aluminum with hydrochloric acid and sodium hydroxide solution, teachers' activities guide students to measure the products of aluminum oxide and their reaction respectively.

Students write the chemical equation and ionic equation of the reaction of alumina with hydrochloric acid and sodium hydroxide solution;

(1) reacts with acidic Al2O3+6HCl ═2AlCl3+3H2O.

Al2O3 + 6H+ ═2 Al3+ + 3H2O

(2) Al2O3+2NaOH ═ 2nalo2+H2O reacts with alkali.

Al2O3 +2OH- ═2 AlO2- + H2O

Teachers' activities present information: from the classification of substances, oxides are divided into acidic oxides and alkaline oxides. Acid oxide refers to the oxide that can generate salt and water when it reacts with alkali. Basic oxides refer to oxides that react with acids to form salts and water. Let the students judge what oxide Al2O3 belongs to according to this information and the knowledge they have learned before.

Summary of student activities: An oxide that can react with both acid and alkali to form salt and water is called amphoteric oxide. Alumina is an amphoteric oxide.

(II) Preparation, properties and uses of aluminum hydroxide

Teachers' activities show that aluminum and alumina can react with hydrochloric acid and sodium hydroxide solution, which shows the knowledge of gender and causes students to think: does aluminum hydroxide hydrate corresponding to alumina also have gender?

There is no ready-made aluminum hydroxide in the laboratory. To study its properties, aluminum hydroxide must be prepared first. How to prepare aluminum hydroxide?

Al2O3 is insoluble in water and cannot react with water. After thinking, the students provided a preparation plan: the soluble aluminum salt solution reacted with alkali to prepare aluminum hydroxide.

Teachers' activities now provide instruments and medicines: test tubes, rubber eyedroppers, Al2(SO4)3 solution, NaOH solution, ammonia water and hydrochloric acid, so that students can prepare aluminum hydroxide through experiments to prove whether it is amphoteric.

Students do experiments, carefully observe the experimental phenomena, and report the results according to the phenomena:

1 and preparation of aluminum hydroxide;

(1) was prepared with Al2(SO4)3 solution and NaOH solution. At first, there was a white precipitate. With the dropping of excessive NaOH solution, the amount of precipitation first increased and then gradually disappeared.

(2) White precipitate appeared at the beginning of preparation with Al2(SO4)3 solution and ammonia water, but the precipitate did not dissolve with excessive ammonia water.

2.Al(OH)3 amphoteric test: white colloidal precipitate, soluble in hydrochloric acid and sodium hydroxide solution.

Teacher activity question: When preparing aluminum hydroxide in the laboratory, which is better, sodium hydroxide solution or ammonia water?

According to the experimental scheme provided by students, the demonstration experiment is carried out, and the control of attention variables in the experiment is emphasized.

Students carefully observe and record the experimental phenomena, and understand the best scheme of preparing aluminum hydroxide in the laboratory through the experimental phenomena: using Al2(SO4)3 solution and ammonia water. Summarize the properties of aluminum hydroxide, and write the chemical equation and ionic equation involved in the experiment.

Teachers' activities come into life: gastric juice contains hydrochloric acid, and people with hyperacidity often feel stomachache, heartburn and easy to spit sour water. Taking metoclopramide (one of the main components is aluminum hydroxide) can relieve stomach discomfort, which shows the alkalinity of aluminum hydroxide.

The alkaline activity of aluminum hydroxide on students is not strong enough to stimulate or corrode the stomach wall, but it can react with acid, reduce the acidity of gastric juice and neutralize excessive gastric acid.

Teachers' activities present information: water-soluble metal hydroxides are stable and not easy to decompose (such as sodium hydroxide and potassium hydroxide). ), their corresponding oxides can react with water; Insoluble metal hydroxides have poor stability and are easily decomposed into metal oxides and water when heated (such as copper hydroxide is decomposed into copper oxide and water when heated).

Ask the students to analyze other properties of aluminum hydroxide according to this information and the known properties of aluminum hydroxide.

Summary of student activities: Aluminum hydroxide is unstable and easy to decompose when heated.

2. Aluminum hydroxide Al2O3+ 3H2O

Teacher activity news: A strong earthquake occurred in Wenchuan in 2008, and most of the water in the disaster area was polluted. However, after the disaster, people will soon have clean and hygienic water to drink. Who's behind this?

Students read the information card to find out the answer and sum up: Al(OH)3 can be used as a water purifying agent.

(C) classroom feedback

1, about aluminum and its compounds is wrong ()

The crucible for melting caustic soda can be made of Al2O3.

B, aluminum exists stably in the air because its surface is covered with a layer of alumina film.

C, alumina is a kind of refractory, and it is a good refractory.

D. Aluminum hydroxide can neutralize gastric acid and can be used to treat stomach diseases.

2. Mix magnesium, aluminum and copper powder, add excessive hydrochloric acid for full reaction, after filtering, add excessive caustic soda solution to the filtrate, and then filter, and the ions in the filtrate are ().

A.AlO2- B.Cu2+ C.Al3+ D.Mg2+

3. In order to completely precipitate Al3+ in alum solution, the appropriate reagent is ().

A.NaOH solution B. hydrochloric acid C. ammonia water D.KOH solution

4, magnesium, aluminum mixed powder 10.2 g, it is dissolved in 500 ml of 4 mol/L hydrochloric acid, if you want to maximize the quality of precipitation, the volume of 4 mol/L sodium hydroxide solution needs to be added is ().

A. 1000 ml B. 500ml C. 100 ml D.1500ml

Description:

1 test students' mastery of the properties and uses of aluminum, alumina and aluminum hydroxide.

Question 2 examines students' mastery of metal activity sequence table and aluminum hydroxide gender.

Question 3 examines students' mastery of the preparation principle of aluminum hydroxide.

Question 4 examines the application of aluminum and its compounds in chemical calculation.

blackboard-writing design

Important compounds of aluminum

I. Alumina

1, physical properties and uses

2, chemical properties-amphoteric oxide

Al2O3 + 6H+ ═ 2 Al3+ + 3H2O

Al2O3 +2OH- ═ 2 AlO2- + H2O

Second, aluminum hydroxide Al(OH)3

1, laboratory preparation of aluminum hydroxide:

Al3++3NH3？ H2O ═ Al(OH)3↓+3NH4+

2. Physical properties

3, chemical properties:

(1) amphoteric hydroxide

Aluminum hydroxide+trihydrate+alumina trihydrate

al(oh)3+oh-═·alo 2-+2h2o

(2) It is easy to decompose when heated.

Aluminum hydroxide alumina+3H2O

Step 4 use