Know how reactants infer products

This test is a comprehensive and comprehensive knowledge, it is difficult to explain clearly in one or two sentences, and what you want to ask should be an organic inference question, if so, it will be easy to solve. Because our high school students are very regular.

First of all, you have to have relevant knowledge reserves, otherwise you don't understand what reactions organic matter has, how do you know what the reaction rules of reactants are, if you don't know, you can't deduce any products, right? That is to say, you must first learn the organic matter in the book, especially the reaction law between functional groups, of course, this is very simple, don't be afraid, the most important thing is the esterification reaction, the hydrolysis and elimination reaction of halogenated hydrocarbons, and the hydrolysis reaction of esters. There is also the catalytic oxidation reaction of alcohol.

Then it is necessary to clearly remember the various reactions, which is an important basis for inferring the products, after all, the reaction conditions are different and the products are different, which is common in organic reactions, such as intramolecular dehydration and intermolecular dehydration of alcohols.

In the end, it is inferred according to the reaction given by the question, which is very simple, just like the situation of one, just look at that part of the reaction, and then draw the scoop according to the gourd.

Of course, there are others, but the probability of occurrence is relatively small, and it will not have much impact if you don't grasp it, such as the number of hydrogen atoms on the carbon atom is different, and the products are also different, such as at least two hydrogen atoms on the carbon atom connected to the hydroxyl group will form Quan, and only one will become a ketone.

Hope it works for you, seek the best.

The determination of the product is a common question type for writing chemical equations, which is generally written in the way of information giving, which is more difficult, needs to be combined with the knowledge learned for reasoning, and is very flexible. Here are some of the key points to determine the product (the most important thing is the reaction principle, i.e. the basics):

1. The redox reaction starts from the valence, for example, there is a reaction of potassium permanganate solution in the question conditions, and there are reducing substances, then potassium permanganate will be reduced, and the determination of the reduction product is the next point I want to say.

2. The form of existence of substances is determined by the chemical environment, such as the reduction product of potassium permanganate, which is divalent manganese ions under strong acidic conditions, potassium manganate in strong alkaline solution, and manganese dioxide under other conditions.

3. The state of the substance depends on the external conditions, for example, the question tells you that the industry uses sodium to reduce potassium chloride to make potassium, many people will not react because the metallicity of potassium is stronger than sodium, in fact, the boiling point of potassium is relatively low, and the existence of sodium in the molten state is in the form of free electrons and sodium ions, because the boiling point of potassium is low, when the temperature of the melt is higher than the boiling point of potassium and lower than the boiling point of other substances, there will be potassium vapor overflow reaction system, so the equation is: Na(L) KCl(L)==NaCl(L) k(g), l, and g represent liquid and gaseous states, respectively.

Mastering these, coupled with a solid basic knowledge, can be completely unpopular with this kind of question.

Hope it helps! Hope!

In fact, it is to memorize the template examples, just pull them out as they are, and the college entrance examination will not be difficult and strange, so it is easy to write out the products based on book examples.

Here are a few examples:

1. Acid-base neutralization reaction: an acid and a base generate a salt and water.

hcl + naoh = nacl + h2o

2. Acids and salts generate new acids and salts

2HCl + Na2CO3 = 2NaCl + CO2 + H2O (This reaction produces carbonic acid, which is unstable and decomposes carbon dioxide).

3. Displacement reaction (hydrogen replaced by active metal):

zn + 2HCL = ZNCL2 + H2 (gas character split number).

In this reaction, you need to know the order table of metal activity, the metal in front of h can replace hydrogen from acid, and copper, mercury, silver, platinum, and gold after h cannot react with acid to replace hydrogen.

4. Replacement reaction (reactive metal replaces non-reactive metal):

fe + cuso4 = cu + feso4

The reaction also needs to know the order table of metal activity, and the metal in the front can be displaced, and the element of the metal in Yushan can be displaced.

5. Redox reaction:

This reaction is more complex, first of all, it determines the type of product based on the mass ratio of reactants (i.e., which reactants will be excessive). Secondly, the type of product is determined by different reaction conditions, such as temperature, concentration, presence of catalyst, etc.

The most obvious example is the redox reaction with the participation of nitric acid, according to the concentration of nitric acid, the type of product is also different, such as the reaction of copper with concentrated nitric acid and the reaction of copper with dilute nitric acid, the reduction product of nitric acid is different.

Summary. You can deduce what the product is based on the elements it contains, as the kind of elements before and after are certainly the same.

How to determine what the product is when the reactants are known.

You can deduce what the product is based on the elements it contains, as the kind of elements before and after are certainly the same.

In the third year of high school, there are some chemical reaction equations, and I still can't tell what the products are.

I also know that the types of elements are constant, but I don't know what exactly is generated.

It is necessary to understand the properties of the reactants, and the principle of the reaction.

It will be clear.

I don't know what to do with Satoshi.

Did you understand everything when the chemistry teacher talked about the reaction equations?

It is recommended to take another look at this piece.

Most of them are just memorized, and few are understood.

Can you recommend what to see?

So, it's important to understand.

Look at the typical types of reactions to the splitting thoughts that the teacher talked about earlier, and think about why, what is the case when the spawn hits the hall for the wanton.

Okay, thank you.

If you don't know how to do it, ask your teachers and classmates.

You are welcome. Do you still have questions, if not, please give me a like, this is very important to me, excuse me, I wish you a happy life, thank you!

It's hard to say, and it's easy to say.

1. Difficult: When the reactants are very complex and we have not seen the same type, it is difficult to judge the products, and it is necessary to confirm them through experiments.

2. Yi: For the chemical reaction in junior high school, it should be very easy to judge.

Example 1: Ignition of magnesium strips and oxygen reaction: then its product is easy to judge, it must be magnesium oxide;

According to the valency, it is known that it is magnesium oxide.

Example 2: Reduction of copper oxide by hydrogen: This is obviously a redox reaction, and the products should be copper and water.

Example 3: Reaction between metallic zinc and dilute sulfuric acid: When you know that this is a displacement reaction, you can judge the product.

Example 4: Reaction between silver nitrate and sodium chloride: If you are familiar with insoluble metal salts and know that silver chloride is insoluble in water, you will know.

The products of this metathesis reaction are silver chloride and sodium nitrate.

Summary. To give you an example, taking redox as an example, we can speculate the product according to the characteristics of oxide and reduct, that is, the law of conservation of atoms, and then use the conservation of electrons and atoms to balance. For metathesis reactions, that is, under the exchange combination, this should be easy to grasp.

For other reactions, some may be derivatives of some equations, which can be written in imitation of learned equations; For example, it will prompt that there is reddish-brown gas in the product, then we can preliminarily conclude that it is NO2, and then speculate on the rest.

Knowing the reactants of the chemical equation, how do you determine the products?

Regarding this question, it is first necessary to know the type of reaction, whether it is a metathesis reaction, or redox, or something else.

To give you an example, taking redox as an example, we can speculate the product according to the characteristics of oxide and reduct, that is, the law of conservation of atoms, and then use the conservation of electrons and atoms to balance. For metathesis reactions, that is, under the exchange combination, this should be easy to grasp. For other reactions, some may be derivatives of some equations, which can be written in imitation of learned equations; For example, it will prompt that there is reddish-brown gas in the product, then we can preliminarily conclude that it is NO2, and then speculate on the rest.

30. What is the human body's emergency response to acetaldehyde in the following phenomena?

a. Blush; b. Abdominal pain; c. Headache after drinking; d. Noisy vomiting.

Correct answer: B. Abdominal pain.

31. What is the chemical reaction in the following reaction equation that does not belong to the oxidation reaction?

A, simple noisy CaCl2+Na2CO3=CaCO3+2Naci; b、c2h5oh+302-2c02+3h20 ;c、2na+2h20=2naoh+h2;d、 cao+h20=ca（oh）2

Correct answer: d, cao+h20=ca(oh)2

1) Combustion: C+O2=CO2

2CO+O2=2CO2CH4+2O2=CO2+2H2O (Description: There are many of these types, all hydrocarbons (called hydrocarbons) are burned to form CO2+H2O) C2H5OH+3O2=2CO2+3H2O (Description: There are also many in this category, and all compounds formed by hydrocarbon, hydroxide and oxygen elements are burned to generate CO2+H2O).

2) Thermal decomposition source: CaCO3== CaO+CO2 (Note: All carbonates that are insoluble in water can be decomposed into metal oxides and CO2 at high temperatures) NH4HCO3== NH3 +CO2 +H2O2NaHCO3== Na2CO3+CO2 +H2O (Say: Zheng Ming:

All bicarbonates can be thermally decomposed to form carbonates, CO2 and H2O)Cu(OH)2(CO3)2== CuO+2CO2 +H2O

3) Carbonate and acid antibisanson: CaCO3 + 2HCl = = = CaCl2 + CO2 +H2O (Note: All carbonates can react with strong acids to form new salts, CO2 and H2O) NaHCO3 + HCl = ==NaCl + CO2 +H2O (Description:

All bicarbonates can react with strong acids to form new salts, CO2 and H2O).

4) Redox reactions (except combustion):

C + 2H2SO4 (concentrated) ==CO2 +2SO2 +2H2OC+4HNO3 (concentrated) ==CO2 +4NO2 +2H2O

The general chemical formula is the anion and cation exchange of reactants, personal summary, wrong also...

Anions and cations are cross-combined, standardized valence, and trimmed.

8 Main Types of Chemical Reactions 1: Inorganic Reactions: Decomposition Reactions (refers to a compound under specific conditions to determine which reaction occurs first, the simplest is to see which product is more stable, and the reaction will be produced first.)

Whether it is a metathesis reaction, redox, or something else to determine whether the valency will change before and after the reaction.

How can you tell? According to the characteristics of the reactants, for example, Hno3, which has strong oxidizing properties, and most of the reactions it participates in are redox reactions).

Once we've decided on the type of reaction, we know where to start.

Take redox, for example.

We can infer the product according to the characteristics of oxides and reductants, that is, the law of conservation of atoms, and then use the conservation of electrons and atoms to balance.

For metathesis reactions, that is, under the exchange combination, this should be easy to grasp.

For other reactions, some may be derivatives of some equations, which can be written in imitation of learned equations;

For example, it will prompt that there is reddish-brown gas in the product, then we can preliminarily conclude that it is NO2, and then speculate on the rest.

Anyway, let's do more training in this area! Hope it helps!

Reaction equations, all have corresponding permutations, and if you understand their characteristics, it is very good to make reaction equations.