Wrong to explain the cause, chemical

1.It is because there are hydrogen bonds between water molecules that increase the boiling point of water, while there are no hydrogen bonds between H2S molecules. 3.Sulfur combustion can only produce SO2, because the conversion of SO2 to SO3 must be carried out under the condition of heating and the presence of a catalyst; 5.

If the reaction is carried out, Baso3 and HCl are generated, which do not meet the rules of acid production: weak acid is made from strong acid; 6.Bleaching refers to the property of a bleach agent that turns a colored substance into a colorless substance through adsorption, compounding, or reduction reaction (the bleach undergoes a reduction reaction); 7.

Dehydration refers to the removal of H and O in a substance according to the ratio of 2:1 to the number of atoms (anhydrous molecules in the substance), and water absorption refers to the property of sucking out the water molecules already present in the substance; 8.Cold and concentrated sulfuric acid will passivate iron and aluminum, so it can be contained in iron containers at room temperature, while dilute sulfuric acid can not passivate iron and aluminum, and the container will continue to react and corrode when contacted; 9.

Copper sulfate is also generated in the reaction, so sulfuric acid also reflects acidity; 10.The valence of S in sulfuric acid and S in sulfur dioxide is adjacent to each other, and according to the principle of redox reaction, adjacent valence substances of the same element do not react with each other.

4. Yes, oxidizing chlorine is greater than ferric ions and greater than sulfur element, so chlorine can oxidize iron into ferric iron, but sulfur cannot.

7. The dryness of concentrated sulfuric acid is due to water absorption, not dehydration. Water absorption is used for drying, and dehydration is a chemical reaction, such as the reaction of sucrose with concentrated sulfuric acid to form carbon.

8. Concentrated sulfuric acid is passivated with iron, and concentrated sulfuric acid can be stored with iron. Dilute sulfuric acid and iron reacted directly, and they couldn't be stopped.

9. It reflects both oxidation and acidity.

7. The desiccant is absorbent.

8. Concentrated sulfuric acid can be stored in iron cans because a dense oxide film is generated, while concentrated sulfuric acid will not continue to react because there are no free hydrogen ions, while dilute sulfuric acid cannot be stored in iron cans because it will react to generate hydrogen.

9. In addition to oxidation, there is also dehydration.

Concentrated sulfuric acid can remove the O h element of some organic matter according to the proportion of H2O and carbonize it. Drying is to remove the water contained in the substance, which is different from the "carbonization" of concentrated sulfuric acid, so it cannot be used as a desiccant;

Concentrated sulfuric acid can passivate the surface of iron without reacting, but dilute sulfuric acid cannot passivate the surface of iron and can react with iron, and dilute sulfuric acid cannot be stored in iron;

Concentrated sulfuric acid reacts with copper to first generate copper oxide, which reflects oxidation; Copper oxide reacts with sulfuric acid to reflect the acidity of sulfuric acid. Therefore, it not only reflects oxidation, but also acidity.

7: Concentrated sulfuric acid is absorbent, not dehydrated. And concentrated sulfuric acid is liquid, as a desiccant? How to place it is a question.

8: Concentrated sulfuric acid should corrode the iron container, and the dilute sulfuric acid is less acidic and will not cause much impact.

9: It also reflects the reducibility of copper.

1 d metathesis. By definition, a chemical reaction has only one product, and in the same way, it is not a decomposition reaction. In the case of substitution, there should be elemental before and after the reaction, and there is no wow in this reaction. It's just an h- and r1- swapping places.

2 a, water is mainly used to absorb SO2 and prevent pollution of the atmosphere.

3 c, the phrase "carbon dioxide is soluble in water" is itself false.

4 b, at the beginning, hydrogen sulfide is added to consume sulfurous acid, and S, which is weakened in acidity, and when all the sulfurous acid is consumed, it is also neutral, that is, pure water. If hydrogen sulfide is added, the acidity of the solution will be enhanced.

Electrode reaction.

The anode is 2cl--2e=cl2

The cathode is an ag++e-=ag reduction product.

The above example is added to the water.

Ag+, Cl-Pb2+, and So42- were precipitated, respectively.

The solution is actually Na2NO3

So their oxidation products.

and the reduction product, respectively.

Oxygen and hydrogen.

So the mass ratio is 8; 1

AG+ +Cl- = AGCL Pb2+ +SO42- = PBSO4 The electrolyzed sodium nitrate solution is water electrolysis in nature.

2H2O = Electrolysis = 2H2 O2 The mass ratio of the oxidation product O2 to the reduction product H2 is: 32:4 =8:1

The electrolysis of this solution is the electrolysis of water, 2H2O = electrolysis = 2H2 + O2, where the mass ratio of oxidation products (O2) to reduction products (H2) is 32:4=8:1

N2O4 is introduced into a container with a volume of 5 L and its concentration is:

n2o4 == 2no2

Starting concentration. 2s transformation concentration.

Concentration at 2s.

It can be seen that the rate of change in the concentration of No2 in the first two seconds is expressed as the concentration of N2O4, so A is wrong.

At 2s, the pressure in the system is *( so b is correct.

Set the N2O4 concentration at equilibrium to x

n2o4 == 2no2

Starting concentration. Transformation concentration 2 (equilibrium concentration x 2 (as can be seen from the title, x +2*(

x=so the conversion rate of N2O4 at equilibrium is so D is wrong, and at equilibrium, the system contains N2O4 and therefore C is wrong.

Suppose that 90% of the sulfuric acid solution with volume v and density of 1 is mixed with 10% sulfuric acid solution with volume v and density of 2, then the total mass of 90% of the sulfuric acid solution is 1*v, the solute mass is 1*v*90%, the total mass of 10% sulfuric acid solution is 2*v, the solute mass is 2*v*10%, and the solute mass fraction after mixing is:

1*v*90%＋ρ2*v*10%）/（ρ1*v＋ρ2*v）＝（1*90%＋ρ2*10%）/（ρ1＋ρ2）＝10%＋ρ1*80%/（ρ1＋ρ2）

By the title, 1> 2, so 2 1 1, so 10% 80% [1 2 1] 10% 80% [1 1] 50%.

So choose A

Let the density of 90% and 10% of the sulfuric acid solution be P1 and P2, respectively, and the volume is V

Then after mixing, solute mass = (

The mass of the mixed solution = (P1+P2)*V

So the solute mass fraction of the mixed solution = (

Then there's the math problem.

p1>p2

So (>

Therefore, the solute mass fraction of the mixed solution is 50%, choose A

In the same volume, 90% must be larger than 10% of the mass, so after mixing, the mass fraction is greater than 50%, and A is selected

1c, k+ positive price.

2a, which is the H2 molecule and the Cl2 molecule, is not an atom.

3 is not. For example, C is a non-metal, there is no negative valence, C and O2 are combined to form CO2, and C is positive in CO2.

b。Elements containing C should be organic, so A and C are wrong. And d is more than 50,000 years old. So b is correct.

It should be B bar, D is more than 50,000 years old, A and C are basically inorganic and have low carbon content, while B has more organic matter and more carbon.

1.It is high, because the NaOH medium mold contains NaCl impurities, which reduces the actual concentration of NaOH solution, so more NaOH solution is required than the standard of the destroyer, so that the measured hydrochloric acid concentration is higher than the actual value.

2.It is low, because the sodium oxide will react with water to form NaOH, and it is easy to obtain that the concentration of the prepared NaOH solution is higher than the standard value, so the code signal is low.

3.Although sodium carbonate will consume hydrochloric acid, 106g of sodium carbonate consumes 1molHCl, and the consumption of the same amount of HCl only needs 80gnaOH.

Because one Na2O reacts with water to produce 2 NaOHs, which is equivalent to 31 masses of Na2O, it takes 1 HCl to produce 1 NaOH

Whereas one Na2CO3 reacts with two HCs.

It costs one HCl equivalent to 53 masses of Na2CO3

The naOH of the blind spine is 40 quality and the NAOH of the fiber is expensive to rent one HCL, so one is on the large side.

A small disadvantage imitation.

No, although e2s > e1s, although the higher the energy and the higher the velocity, the easier it is to break free from the shackles of nuclear gravity.

But that's statistical.

It is also possible for 1s electrons to run outside of 2s electrons, but the probability is relatively small, and the probability of 1s appearing in 2s is large, so it is said that e2s > e1s

Yes, the higher the energy and the higher the velocity, the easier it is to break free from the shackles of nuclear gravity.