Chemical concept analysis, chemical concept understanding

I won't talk about the first two, the above two are right, as for the third, the example on the second floor is wrong.

The third sentence is also wrong, for example, metal intercompounds are compounds but do not contain non-metallic elements, such as CaCu5, MgCu2, Cuzn, Ag3Al, Cu9Al4, Cu3Sn and so on.

1 False Counterexample: ammonium salt.

2. Wrong ammonia. 3 pairs.

All three sentences are wrong.

1. Such as: ammonium salt; 2. Such as: ammonia; 3. Such as: water.

1. If X can displace Y from its salt solution, is it correct that X is more non-metallic than Y? The answer is correct, I think it's wrong, I can't figure it out.

I also think that this sentence is wrong, and it may also be the displacement between metals, such as FE replacing Cu, that is, the metallicity of X is stronger than Y.

If it is stated that non-metal x can replace non-metal y, then it is considered correct in "high school".

Because there will be a reaction in the race, i2

2kclo3

cl22kio3

2. If i1(x) > i1(y), then the non-metallic property of x is stronger than y, is it correct? The answer is correct, I think it is wrong, because the first ionization energy of n is greater than the first ionization energy of o, but o has to be more non-metallic than n?

What you said is right, whether the first ionization can be used as a basis for metallicity and non-metallic property is two special cases.

mgal，no

There is only ionization equilibrium in acetic acid solution, no hydrolysis equilibrium!

The distinction between ionization equilibrium and hydrolytic equilibrium can be distinguished by combining the species of solute:

There is ionization equilibrium in a weak acid or alkaline solution, and a hydrolyzable equilibrium exists in a salt solution that can be hydrolyzed!

For NaHCO3, it is both a weak acid and a salt. So it has both ionization equilibrium and hydrolytic equilibrium.

Le Chattle's principle: If you change one of the conditions that affect the equilibrium (e.g. concentration, pressure, temperature, etc.), the equilibrium moves in a direction that can attenuate the change. 1) Concentration:

Increasing the concentration of a reactant is in the direction of decreasing the concentration of this reactant, that is, the reaction is proceeding in the positive direction. Decreasing the concentration of a product results in the reaction in the direction of increasing the concentration of the product, i.e., the reaction proceeds in the opposite direction. Vice versa.

2) Pressure: If the pressure of a gaseous reactant is increased, the reaction will be carried out in the direction of reducing the pressure of the reactant, that is, the reaction will be carried out in the positive direction. Decreasing the pressure of a gaseous product results in the direction of increasing the pressure of this product, i.e., the reaction proceeds in the opposite direction.

Vice versa. 3) Temperature: If the reaction temperature is increased, the reaction will be carried out in the direction of reducing heat, that is, the exothermic reaction will be carried out in the opposite direction, and the endothermic reaction will be carried out in the forward direction; When the temperature is lowered, the reaction proceeds in the direction of heat generation, that is, the exothermic reaction proceeds in the forward direction and the endothermic reaction proceeds in the reverse direction.

4) Catalyst: only change the speed of the reaction, do not affect the change of equilibrium, that is, the degree of influence on the forward and reverse reactions is the same. From the above analysis, it can be seen that:

Some of the situations that usually arise fall within the scope of Le Chatre's principle. Therefore, when we encounter a problem involving balanced movement, as long as we correctly apply Le Chatre's principle to analyze, we can come up with a suitable answer. Derivation.

The concept that a molecule is a particle that maintains the chemical properties of a substance is a molecule, is certainly correct.

For a substance composed of molecules, its chemical properties are of course maintained by molecules, that is, the chemical properties of the substance are the same as the chemical properties of one of his molecules. For example, oxygen is combustible, and its flammability is, of course, maintained by oxygen molecules, in other words, oxygen molecules.

The statement that a molecule is a particle that makes up matter is certainly true; This is a description of what particles are made of matter. In nature, some substances are made up of molecules, some are made of atoms, and some are made of ions. So a molecule is just one of the particles that make up matter.

The difference is that the first sentence emphasizes that molecules can be formed into substances, while the second sentence emphasizes that older molecules can maintain the chemical brightness and chaotic properties of substances.

The first sentence is too general and reflects only one part of the molecule's characteristics, while the second sentence shows the smallest pin pin particles that distinguishes the molecule from other particles—maintaining the chemical properties of the substance.

Of course, molecules are also particles that make up the constituent substances, but the first sentence is not painful, and the second sentence deals with definitions.

Encyclopedia definition: A molecule is the smallest unit in a substance that can exist independently and is relatively stable and maintains the physical and chemical properties of the substance.

Answer: 4mol l 2mol l 90ml

Detailed explanation (the number in front of the question is the number in the blank space of the question).

1。250ml solution contains 40gnaoh, 1l can be divided into 4 250ml, so it contains 4x40=160gnaoh

Because the molar mass of NaOH (molar mass = relative molecular mass, one mole of the mass of the substance, in g mol) is:

23 (molar mass of na) + 16 (molar mass of oxygen) + 1 (molar mass of hydrogen) = 40g mol, so 160g is 4 40g, which is 4mol So the first empty is 4mol l.

2。Because 50 ml is 1 20 of 1 L, NaOH in 50 ml of A solution is 1 20 of NaOH in 1 L, which is 1 20x4mol =

to liter (100 ml = mass concentration of the substance in the solution.

3。The mass of the solution that is used to mix with B = density x volume = so where the mass of NaOH is mass molar mass = amount of substance), so the amount of total substance is the amount of NaOH in the previous B solution 2mol plus the amount of substance in the latter solution is equal to, and the concentration is.

4。.According to the equation NaOH + HCl = NaCl + H2O, it is known that NaOH and HCl react in the ratio of the amount of matter to 1:1 (the coefficients in front of the two in the equation are 1, so they are 1:

1）。So the amount of HCL required is as much as the amount of the substance of NaOH, for, so volume=, so volume=

Answer: 4 2 90

Analysis: The relative molecular mass of NaOH is 40g mol, and 40g 40 (g mol) = 1mol is NaOH is, so the concentration of A is 1mol. 50ml of A becomes B after doubling the volume, so the concentration of B is half of A, i.e. 2mol l.

The mass of the solution added after that is 10 ml, of which the mass of NaOH is.

The mass of NaOH in solution B is 2mol l, so the concentration of solution C is (. The amount of the substance in which NaOH is approximately, corresponding to the need for HCl to react, so it is required.

The word "chemistry" is defined literally as "the science of change". Chemistry, like physics, is the basic science of the natural sciences. Chemistry is a natural science based on experiments.

Mendeleev's periodic table of chemical elements greatly contributed to the development of chemistry. Nowadays, many people call chemistry the "central science" because chemistry is at the heart of some scientific disciplines, such as materials science, nanotechnology, biochemistry, etc. Chemistry is a natural science that studies the composition, structure, properties, and changes of matter at the atomic level, which is also the core basis of chemical change.

There are five sub-disciplines under Modern Chemistry: Inorganic Chemistry, Organic Chemistry, Physical Chemistry, Analytical Chemistry and Polymer Chemistry.

1. Yes, this is one of the criteria for the non-metallic nature of the element, and the topic is to ask the acid anion.

2. The answer is wrong.

1. The chemical equilibrium constant refers to the fact that at a certain temperature, the reversible reaction starts from the positive reaction or the reverse reaction, and regardless of the initial concentration of the reactants, and finally reaches equilibrium. For example, for a reversible chemical reaction where Ma+NB PC+QD reaches chemical equilibrium at a certain temperature, the expression of the equilibrium constant is:

At the high school level, the chemical equilibrium constant is only affected by temperature and has nothing to do with concentration or pressure.

When writing balance constant expressions, pay attention to the following questions:

When applying the equilibrium constant expression, the concentration of water molecules in a dilute solution can be omitted. Because the density of the dilute solution is close to 1 g ml. The amount concentration of the substance of water is mol l.

In the process of chemical change, the change of water quantity has little effect on the change of water concentration, so the concentration of water is a constant, which can be incorporated into the equilibrium constant.

For reactions in a solution that does not use water as a solvent, the concentration of the solvent is likewise constant.

When there are solid substances involved in the reaction, the intermolecular collision can only be carried out on the surface of the solid, and the amount and concentration of the solid substance has no effect on the reaction rate and equilibrium, therefore, the "concentration" of the solid is taken as a constant, and the concentration of the solid is not written in the equilibrium constant expression.

The expression of the chemical equilibrium constant is related to the way the chemical equation is written. For the same chemical reaction, due to the different ways of writing, the stoichiometric numbers of each reactant and product are different, and the equilibrium constant is different. But these equilibrium constants can be converted to each other.

Different chemical equilibrium systems have different equilibrium constants. A large equilibrium constant indicates that the equilibrium concentration of the product is larger, and the equilibrium concentration of the reactant is relatively small, indicating that the reaction is carried out more completely. Thus, the magnitude of the equilibrium constant can indicate how well the reaction is carried out.

The k>10 5 reaction is considered to be more complete (i.e., irreversible) and the k<10 (-5) reaction is difficult to proceed (i.e., no reaction).

The magnitude of the equilibrium constant can be used to determine how well the reaction is proceeding.

2. Other chemical equilibrium constants in high school (such as hydrolysis equilibrium constant, ionization equilibrium constant, insoluble solubility product constant, etc.) are the same as the chemical equilibrium writing method described above.

1) The ionization equilibrium constant Ka and Kb are depresented, the weak acid is represented by Ka, and the weak alkali is denoted by Kb.

2) The hydrolytic equilibrium constant is expressed by kh, and the hydrolytic equilibrium constant can be calculated by derivation formula in addition to the original expression, kh=kw ka, kh=kw kb.

3) The solubility product constant of insoluble matter is expressed by ksp. Hope.