According to Ms. Huynh Thi Thanh Huong, Team Leader of Phan Chau Trinh High School (Da Nang City), the high school chemistry program consists of two main parts, inorganic and organic.
Students studying for exams at Phan Chau Trinh High School (Da Nang). The key knowledge in the high school graduation exam is in the 12th grade Chemistry program, the number of questions related to the 11th grade program is very small and mainly combined with the general knowledge question. Reinforce basic theory Ms. Huong said: Chemistry is an experimental science with a large amount of knowledge, ranging from theory at the level of awareness and understanding to exercises at a high level of application and application. According to Ms. Huong, from qualitative to quantitative exercises, experimental questions to questions related to economic, social, and environmental issues… most students focus on conquering Quantitative exercises with the desire to achieve high scores in the exam but forget that quantitative exercises only account for 25% of the exam structure (about 10 questions/40 questions of the Chemistry exam). Click on the image to view the content. “Students should have a more realistic view of the exam questions, thereby increasing the amount of time to review and consolidate basic theory into a fixed source of capital for themselves before each exam,” Ms. Huong said. In addition, Ms. Huong illustrates the learning method for the knowledge content on metal corrosion, metal preparation in the metal outline section. Systematic knowledge to grasp includes: Corrosion of metals and metal processing. Specifically, metal corrosion is the destruction of metal or alloy due to the action of substances in the surrounding environment (M > Mn + + ne). In particular, metal corrosion has two forms: chemical corrosion and electrochemical corrosion. Chemical Corrosion: Corrosion reaction does not generate electric current. And electrochemical corrosion: Corrosion reaction simultaneously generates electric current. Electrochemical corrosion occurs when in a material there are different electrodes, in contact with each other and placed in an electrolyte environment. Rust (corrosion of cast iron and steel objects in moist air, acid …): Fe-Anode (-): Fe > Fe2+ + 2e (Oxidation) C-Catot (+): O2 + 2H 2O + 4e > 4OH– (Reduction) Or: O2 + 4H+ + 4e > 2H2O Rust generation reaction: 2Fe + 3/2O2 + nH2O > Fe2O3.nH2O The similarity between chemical corrosion and electrochemical corrosion is the oxidation – reduction process. But chemical corrosion does not generate electric current, metal corrodes slowly; while electrochemical corrosion generates electric current, metal is corroded quickly. For metal protection against corrosion, there will be two methods of surface protection: Isolate metal from the environment by coating the metal surface with environmentally sustainable substances such as grease, paint, and plating. metal, enameled; also electrochemical protection that binds a metal to another more active metal. For example, attaching zinc to the steel hull (submersible part) will corrode the zinc and protect the hull. Preparation of metals, the principle of reducing metal ions to metal atoms (Mn + + ne > M). With methods of electro-treatment, heat-treatment and hydro-treatment. Formula for expressing Faraday’s law: (according to the number of moles of electrons exchanged). m: Mass of substance collected at the electrode (g) A: Molar mass of the substance obtained at the electrode (g/mol) n: Number of electrons exchanged I: Amperage (A) F: Faraday’s constant (F = 96500) Students need to draw connections, simple ways of remembering when doing related types of work. For example how to solve the question package about metal modulation methods like: Which of the following metals can be prepared by hydrometallurgy? A. Ca. B. Na. C. Mg. D. Cu. Which of the following metals can be prepared by solution electrolysis? A. Ag. B. Na. C. Ba. D. Al. You can use diagrams for this type of question like this: K, Ba, Na, Mg, Al – Zn, Fe, Ni, Sn, Pb, Cu, Hg, Ag, Pt, Au Molten electrolysis Solution electrolysis, heat treatment, hydrometallurgy. The way to do the test effectively is to calmly read the exam questions. Hundred or used manually Ms. Huong said: When reviewing, students need to remember the principle “Hundred or not with familiar hands”, repeating information as much as possible, the deeper the memory, the easier it is to recall. So do as many exercises as possible. When doing the test, there must be a relationship of knowledge, good points, and skills that need to be applied to each type of post; exchange materials with friends and teachers. Click on the image to view the content. “For lessons on mainstream theory, students need to master the definition and concept, understand the essence of that definition and concept, and know how to apply it to solve related questions. For the lesson on quality, candidates need to firmly grasp the name, properties, relationship between structure and properties, and practical application”, Ms. Huong said. According to Ms. Huong, in order to solve chemistry exercises, students first need to master the theory, then practice more skills in applying theory to specific exercises, problem analysis skills, and using tricks. calculate… According to Ms. Huong, the effective way to do the test is to calmly read the exam questions. With the form of theoretical questions, quickly read through the sentences to see the answers immediately, the questions are left to do later. With the question type of counting the number of true/false statements, in each statement should note the points in the topic. wrong, exception, it will be more convenient for you to check your work again. With the form of quantitative exercises, which sentences are familiar, have been met and done first. Which sentences are difficult and novel to do later and when done, you should combine looking at the answer because some sentences can be easier to navigate from the answer.
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