How to learn electrochemistry well? Can anyone help summarize the important rules.

In electrochemistry, it is best to understand the principles of galvanic cells, electrolytic cells, etc.

The working principle of galvanic battery galvanic cell is to spontaneously carry out the oxidation reaction and reduction reaction of the redox reaction on the negative and positive electrodes of the galvanic cell respectively, so as to generate current in the external circuit. Judgment of the electrode of the galvanic battery: Negative electrode:

one pole of electron outflow; the pole where the oxidation reaction takes place; A pole of a more lively metal. Positive electrode: the pole where electrons flow in; the pole where the reduction reaction takes place; A pole of a relatively inactive metal or other conductor.

In galvanic cells, the outer circuit conducts electricity with electrons, and in the electrolyte solution, it conducts with ions. Determination of galvanic battery: (1) First analyze whether there is an external circuit, the electrolytic cell with external power supply, and the galvanic battery without external power supply; Then according to the analysis and judgment of the formation conditions of the galvanic battery, it is mainly "four looks":

Look at the electrodes - the two poles are conductors and there is a difference in activity (the electrodes of fuel cells are generally inert); Look at the solution – the poles are inserted into the solution; Look at the loop – form a closed loop or direct contact between the poles; Look at the essence - whether there is a redox reaction or not. (2) When multiple cells are connected, but there is no external power supply, the pool with the largest difference in the activity of the two poles is the galvanic battery, and the other pools can be regarded as electrolytic cells.

Electrolysis is the process of passing an electric current through an electrolyte solution (or molten electrolyte) to cause a redox reaction at the cathode and anode. Electrolysis is the condition in which an electric current is passed through an electrolyte solution (or molten electrolyte) for an electrolytic reaction to occur? Connect the DC power supply to the cathode and cathode cathode:

Connected to the negative electrode of the power supply as the cathode Anode: Connected to the positive electrode of the power supply as the anode The two electrodes are in the electrolyte solution or molten electrolyte The two electrodes form a closed loop.

These two should be the most typical electrochemical experiments, of course, the most important thing in science is to do more exercises.

First understand the principle and then do the problem.

Senior year of high school, let's do more practice, I'm from here.

1. Distinguish the cathode and anode, the one connected to the positive electrode of the power supply is the anode, the one connected to the negative electrode of the power supply is the cathode, and the reaction of the two poles is "cation oxygen cathode return".

2. Correctly judge the product, write the electrode reaction formula, and pay attention to the conservation of electrons for gain and loss.

1) The judgment of the anode product first looks at the electrode, if the active electrode is used as the anode, the electrode material loses electrons, and the electrode is dissolved (note: iron is dissolved as an anode to generate Fe2, not Fe3); In the case of an inert electrode, the electron-losing ability of the anion in the solution is to be s2 >i > br > cl > oh (water).

2) The judgment of the cathode product is directly judged according to the discharge sequence of the cations

AG>HG2>Fe3>Cu2>H (acid)> PB2>Fe2>Zn2>H (water).

3. Measures to restore the solution in the electrolytic cell.

The problem of the return of the electrolyte solution to its original state after electrolysis should be analyzed by the conservation of mass method, and the general situation is to add compounds with anode products and cathode products, that is, what is precipitated from the solution, what is added.

1) The type of electrolyte solution electrolyzed with an inert electrode is shown in the table below (corresponding to incomplete discharge of electrolyte ions).

2) In special cases, such as electrolysis of CuSO4 solution with an inert electrode, before A, Cu2 is completely discharged, the electrolysis shows that 2Cu+O2 can be restored by adding CuO or CuCO3 (i.e., CuO and CO2, CO2 escaping from the solution).

B, Cu2 After the complete discharge, it is equivalent to continue to electrolyze water to release 2H2 and O2, which is equivalent to H2O, that is, 2Cu + O2 and 2H2, O2 are co-precipitated from the solution, CuO and H2O need to be added, Cu(Oh)2 or Cu2(Oh)2CO3 should be added [that is, Cu(Oh)2 and CO2, CO2 escapes from the solution] for recovery.

How to say it, people are born with different understanding, even think that the most important thing is to listen carefully in class, seriously, what the teacher says, quickly take the pen to calculate, maintain a high degree of concentration, and then if you think she didn't understand what he said, quickly record it, and discuss it with your classmates after class - this is the method, because my chemistry grades last semester were very bad, because I didn't pay attention to listening in class, this semester changed a chemistry class teacher, As a result, I rushed from the back of the crane to the experimental class because I had to listen to it in class, and the average score = = was rushed

Of course, it may not be able to continue, but listening in class is the most important thing, and listening to lectures is efficient and only speaking.

=And then the focus of these two parts===

Electrochemistry, the essence, the essence, the essence is redox. How to say it, get the things in the book right, fuel cells or something, the examples in the book are the most typical, to remember.

What is from the balance of the old void = = that I don't think I'm bad, but just in terms of the test hail burning test, the hydrolysis part: the most important thing is that Meng! If you see one, choose it!

So you're sure to win, believe me, it's stupid, really. In addition, Xianchang said that two conservations should be used, just write a few more.

Ionization part + PH: Just calculate, calculate hard, toss a few times to understand.

= That's all. If it helps, please give a good review, thank you in advance.

Key Splitting of the Ion Equation: 1 The change of valence figure out and develop the habit of price labeling 2. Practice writing the single-step electronic gain and loss equation (gentry (increased valency) Shi (loss of electrons) and flower raising (oxidized) is a reducing agent) 3. Find out the chemical strength of the product (reducing and oxidizing) (it is easy to remember the laws of the periodic table) 4. The strange metal Al can be dissolved in a strong base, Al is the electrode, and when the strong base is the electrolyte, Al loses electron, and the valency is increased and oxidized If you are in the third year of high school, you should pay attention to this chapter, oh, I wish you a good university.

This needs more practice, you can come and sign up for a training class!

One. Determine the type of electrode reaction.

Memory requires skills, and through the memory of yin and yang contradictions, the electrode reaction type is to remember one: it is enough for the anode to lose electrons, and the yang is lost! Two words, the opposite of the contradiction The cathode is to get electrons, and then the contradiction is the opposite, the opposite of the electrolytic cell anode is the positive electrode of the galvanic battery, and the two reactions cannot be the same, so the positive electrode gets electrons, and then the contradiction is opposite, how about the negative electrode?

Lost electrons! So as long as you write the two words Yang Lost, everything comes out. I did the steps of the question, 1

The oxidation reaction of the reducing agent undergoes an oxidation reaction to obtain the oxidation product; The oxidant undergoes a reduction reaction to obtain the reduction product; The cathode oxidant undergoes a reduction reaction to obtain the reduction product; The negative electrode reducing agent undergoes an oxidation reaction to obtain the oxidation product.

Two. Determine the reaction formula and the number of electrons gained and lost at each pole of organic fuel.

1. It must be remembered that oxygen must be the positive electrode, and the organic fuel must be the negative electrode. Write organic as "something" + n (h2o), and count how many c's and several h's in "something" are all valued as 0, and then c will change to co2A C loses 4 electrons, in the same way, an H to one-half H2O loses 1 electron, such as CH3OH can be written as CH2H2O, so a total of 6 electrons are lost.

2. The general electronic equation for the positive electrode is the same as O2-4E +2H2O===4OHThe cathode can be subtracted by the ordinary organic fuel combustion equation. However, it should be noted that the generation of CO2 is a neutral or acidic electrolyte solution, if it is an alkaline electrolyte solution, the generated CO2 and 2OH to form carbonate ions, the reason why it is not bicarbonate and ions is because of excessive OH.

After writing it, it is added to the fuel combustion equation to give the total equation, minus the positive electrode O2....The equation can then get the positive equation.

Do more questions, do research, and summarize more, and it's OK

Familiar with ionic reaction formulas, electromotive force under various acid and base conditions.

Reading Cao Chunan's book is very classic.

Why is electricity a headache for so many people? Because electricity is more abstract than the number of excitations, some problems can only rely on imagination, and circuit diagrams have high requirements for thinking ability, so many people fall into the pit.

First of all, you need to do a good job of pre-studying, understanding the basic concepts, such as the meaning of electricity, especially the circuit diagram to read several times.

When you are in class, you should listen carefully to the class, especially when the teacher is doing experiments, you have to study seriously, and you can also ask the teacher to borrow experimental instruments to do experiments for you after class, so as to enhance your practical ability to calm socks.

Do more exercises, although Bi Yan does not advocate the tactics of sea of questions, but the science subject needs to be practiced, so that it can be more flexible. Remember, it is very important to preview and summarize, after the preview, do the questions yourself, and then summarize some methods, such as what is the reason why the light bulb does not light up, you should memorize it, because you often take the test, and you also know how to measure.

Believe in yourself and don't be discouraged, it's not hard now. It's not until you're in the third year of junior high school that you learn about electricity, and you don't have to think about it if you don't drive you crazy.

As long as you do a good job of pre-studying, it is not so difficult to summarize often, and it is better for you to be one or two lessons ahead of the teacher.

Memorize the formula, analyze the known conditions, convert the words in the conditions into physical formulas, and then analyze the known quantities required according to the general formula.

1 Understand the composition of galvanic cells There are three indispensable conditions for the composition of galvanic batteries, and these three conditions are:

1) Electrode consists of two pieces of metal with different active properties as the two electrodes of the galvanic battery. The reactive metal is the negative electrode of the battery, and the inactive metal (or non-metallic conductor) is the positive electrode of the battery.

2) Electrolyte solution According to the electrolytic material, acid, alkali, and salt solutions can be selected as the composition of the electrolyte solution.

3) The wire is used to connect the two poles, so that the two poles immersed in the electrolyte solution form a closed loop to form a working galvanic battery.