High School Chemistry: The core test site of organic experiments+answering routines, it is recommended to collect it!

High School Chemistry: The core test site of organic experiments+answering routines, it is recommended to collect it!

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1. Heating method

Organic experiments often need heating, and different experiments may be different

① Heat the alcohol light. The flame temperature of alcohol lamps is generally 400-500 ° C, so experiments with less temperature can be heated with alcohol lights. Organic experiments heated with alcohol lamps in the textbook are: "Ethylene Preparation Experiment", "Ethyl Ethyl Ethyl Making Experiment", and "Petroleum Circulation Experiment".

② Water bath heating. The temperature of the water bath does not exceed 100 ° C. Organic experiments heated with water baths in the textbook include: "Silver Mirror Experiment (including all silver mirror experiments including aldehyde, sugar, etc.)," ​​nitro benzene production experiment (water bath temperature is 55-60 ° C) "," Hydrolysis experiments of ethyl acetate (water bath temperature is 70-80 ° C) "and" sugar (including two sugar, starch, and cellulose, etc.) hydrolyzing experiments (hot water bath) ".

③ Organic experiments with temperaturemeter temperature measurement: "Nitroben benzene production experiments" and "the production experiment of ethyl acetate" (the thermometer in the two experiments above the experiments are inserted in the water bath liquid in the reaction liquid, Imer the temperature of the water bath), "the laboratory production experiment of ethylene" (the temperature of the water and silver ball inserted into the reaction solution, the temperature of the reaction solution) and the "oil distillation experiment" (thermometer water and silver ball should be inserted at the mouth of the distilled bottle pipe, Determine the temperature of the distillation).

2. Use of catalyst

① Experiments of sulfuric acid for catalysts: "Ethylene's Disposal Experiment", "Nitrobenzene -based Express Experiment", "Ethyl acetate's Expressive Experiment", "Cellulose Nitrofate Experiment", "Sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar (sugar ( Including two sugar, starch and cellulose) hydrolysis experiments "and" hydrolysis experiments of ethyl acetate ".

The catalysts of the first four experiments are concentrated sulfuric acid, and the catalyst of the latter two experiments is dilute sulfuric acid. Among them, the last experiment can also be used as a catalyst with sodium hydroxide solution

② Experiment of iron for catalyst: The production of bromine (actual catalytic is a bromide generated by bromine and iron reaction).

③The experiment of copper or silver as a catalyst: alcohol's dewravioxid catalytic oxidation reaction.

④ Experiment of nickel catalyst: acetaldehyde catalytic oxidation to acidic reaction.

⑤ Other unsaturated organic matter or benzene is the same with hydrogen, hydrogen, hydrogen, and water. To avoid confusion, you can directly write a catalyst.

3. Pay attention to the amount of the reactor

Organic experiments should pay attention to strictly control the amount of reactors and the ratio of each reactor. For example, the "preparation of ethylene" must pay attention to the proportion of ethanol and concentrated sulfuric acid is 1: 3, and the amount required should not be too much, otherwise the reactant will heal too much too much. Slow, there are many side reactions, which affects the yield of ethylene.

4. Pay attention to cooling

The reactions and products in organic experiments are mostly volatile harmful substances, so you must pay attention to cooling the reactors and products sent out.

① Experiment to cool water (with condensation tube) cooling experiments: "Differential Water Making Experiment" and "Dragon Experiment of Petroleum".

② Experiments with air cooling (connecting reaction device with long glass tube): "Nitrobenzene's production experiments", "decoration experiments of phenolic tree ester", "molecoticate production experiment", "catalytic paradis catalytic catalysis Cracking experiments "and" decapyate experiment ".

The purpose of these experiments to cool is to reduce the volatilization of reactors or generics, which not only ensures the smooth progress of the experiment, but also reduces the harm of these volatiles to human pollution to the environment.

5. Pay attention to removing miscellaneous

Organic experiments often have more side reactions, resulting in many impurities in the product. In order to ensure the purity of the product, we must pay attention to purifying the product and removing the product. For example, in the "Ethylene Preparation Experiment", ethylene often contains impurity gases such as CO2 and SO2, which can pass this mixed gas into a thick alkali solution to remove acidic gases; Preparation experiments, the products contain bromine and NO2 in the products of bromine and nitrobene, so the product can be washed with thick alkali solution.

6. Pay attention to stirring

Note that constantly stirring is also a attention to organic experiments. For example, "concentrated sulfuric acid makes sucrose dehydration experiments" (also known as "black bread" experiment) (the purpose is to quickly mix concentrated sulfuric acid with sucrose and respond sharply in a short period of time, so as to reflect the gases released and a large amount of heat generated by a large amount of heat. The preparation of alcoholic acid mixture in the "ethylene preparation experiment" in the "ethylene preparation experiment" is preparation.

7. Pay attention to the use

The organic experiments of Zuishi need to be used:

① Experiment to make ethylene in the laboratory;

② Petroleum distillation experiment.

8. Pay attention to the treatment of exhaust

Organic experiments are often volatilized or produced by harmful gases, so it must be harmless to the tail gas of this harmful gase.

① In the production experiment of methane, ethylene, and acetylene, flammable tail gas can be burned;

② "Devinzide's production experiment" and "preparation experiment of nitrobenzene" can be used to return to the method of cooling to return the harmful volatile objects.

The solution of the question "routine" and template

The briefing question is often based on the knowledge of chemical experiments and the principle of chemical reactions. It mainly examines the application of the principles of chemical balance movement, and the description of experimental purposes and phenomena.

1. Accurate description of the application of chemical balance movement principles

(1) Answers to the questions

① Write the formula of reversible reaction.

② The condition of change.

③ How to move the balance.

④ What results do the balance movement cause. (2) Score points and keywords

Answer such topics should pay attention to the answer to the narrative method: reversible reaction+condition change+balance movement direction+balance mobile result.

① Reverse reactions: Chemical equations or ion equations.

② Condition changes: Only "one condition" change, other conditions remain unchanged.

③ Balanced movement direction: forward (or reverse) movement.

④ Balanced Movement Results: What changes or impacts of certain physical quantities have happened.

2. The main points of answering the cause, purpose, and role of the experimental operation

(1) Answers to the questions

① Clarify the experimental purpose: What to do?

② Clarify the purpose of operation: Why do this?

③ Clear conclusion: What will happen if you do this? What is the reason?

(2) Score points and keywords

① Operation: How to be "proud"? Why did you do this".

② Function: There are clear conclusions, judgments, and reasons.

3. Accurate and comprehensive description of experimental phenomena

(1) Answers to the questions

① The phenomenon description should be seen, heard, touched, and heard.

② Phenomenon description should be accurate: such as A test tube ..., B is there ...

③ According to the description of the "phenomenon + conclusion" format, the conclusions are avoided, and the phenomenon of conclusions is not distinguished, the phenomenon of conclusions, and the name of the specific generic.

(2) Score points and keywords

For different states, you can answer the templates below:

① The g color in the solution changes from ... to ..., the liquid surface rises or decreases (the fluid variance), the solution becomes turbid, generated (generated) ... The solution is reflected), and the liquid overflow is overflow.

② Solid: A large amount of bubbles are generated on the surface, gradually dissolved, the volume gradually becomes smaller (thin), the color changes from ... .... ...

③ Gas: Given ... color (taste) gas, gas changes from ... color to ... color, first change ... then ... (deepen, lighter, fade), etc.

4. The answer template for experimental operation

(1) Check whether the sedimentation is completely answering template

Take a little last washing filter and drip in a small amount ... the solution (reagent). If ... (phenomenon), it means that it has been washed completely.

Note: You should pay attention to the four score points: sampling+reagent+phenomenon+conclusion.

① Sampling: To take "a little last time" washing the filter fluid.

② Reagent: Choose a reasonable reagent.

③ Phenomenon: There is a clear description of phenomenon.

④ Conclusion: Conclusion is based on the phenomenon.

(2) Judgment answer template at the end of the titration

After dripping the last drop ... the standard solution, the solution becomes ... color, and the original color is not restored in half a minute.

(3) The answer template used in test strips

Take a small pH test strip on the surface dish, use the dry and clean glass rod dipped in a small amount of test liquid, and click on the pH test paper. After the test strip is discolored, compare with the standard comparison card.

Answer such topics. Pay attention to three score points and keywords: dipping the test solution+point sample+comparison reading.

① Dip the solution to be tested: Use it for dry and clean glass rod dipped in the survey liquid.

② Click the sample: click on the test strip.

③ Comparison 2 and standard ratio card comparison reading.

5. Accurate description of gas tight inspection

(1) Answers to the questions

① Applicable method: micro -heat or liquid difference (seal) method.

② Form a closed system.

③ Operation method.

④ Phenomenon and conclusions.

(2) Keywords and score points

① Answer such questions with clear keywords:

a. Micro heat method inspection: closed, micro -heat, bubbles, water columns.

b. List differences are checked: closed, liquid difference.

② The answer must be answered according to the "operation + phenomenon + conclusion":

a. Operation: How to form a "closed system fly" how to "heated".

b. Phenomenon: Observe the changes in bubbles or liquid surfaces and point out the relevant experimental phenomenon.

c. Conclusion: Through ... phenomenon shows good qi.

6. Answer specifications for gas inspection

Put the gas ... (operation) ... solution (reagent), ... (phenomenon).

Note: Answer such topics. Pay attention to three score points: operate ten reagents + results.

(1) Operation: There must be obvious verbs, "join", "people", etc., "pour in" is incorrect, and other operations such as "ignition" can also be used.

(2) Reagents: Select the reagent accurate.

(3) Results: There are obvious phenomena or conclusions and judgments.

7. Answer template for the role of reagents

(1) Answers to the questions

① What is the role of reagents?

② What is the purpose to be achieved?

(2) Score points and keywords

① The role of the role: "remove", "prevent", "suppress", "to ...", etc., the answer should be accurate.

② The purpose of the role: "function" is "...", "purpose" is "...". The answer should be accurate and comprehensive.

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