10 points in high school sophomore chemistry explained thank you

1 First of all, the oxidation reaction occurs at the negative electrode of the hydrogen-oxygen fuel cell.

4oh-=2h2o+o2+4e-

2 i.e. 2na

2 is 1mol 1mol has na molecules, so CH4 and C2H4 have a total number of molecules, and because there are 4 hydrogen atoms in each molecule, there are 4 hydrogen atoms

3 1L* (without hydrolysis).

a. The role of solid oxides is to allow electrons to pass through the battery. Yes, the oxidation reaction occurs at the negative electrode of the hydrogen-oxygen fuel cell.

So the number of electrons is 2na.

b. In SiO2 crystals, the smallest unit ring composed of Si and O has 8 atoms. In 12 g of diamond, the number of covalent bonds containing C—C is 4NaC, and there must be anions in the crystals of cation-containing compounds. It's 1mol 1mol has na molecules, so CH4 and C2H4 have a total number of molecules, and because there are 4 hydrogen atoms in each molecule, there are 4 hydrogen atoms

c. 1L* (without considering hydrolysis).

A, the gas is, and the negative electrode is O2 that has a reduction reaction, so the number of electrons is 2mol

b, each molecule is four hydrogen atoms, so it is 4mol

c, it is also a truth, (but you can ignore hydrolysis).

The answer is d

Solution 1: The average molecular formula is.

Only d is compliant

At this time, the volume ratio of C2H6 to C3H8 is 1:1

Solution 2: Because the reaction is measured at the same temperature and pressure.

So the volume ratio is equal to the ratio of the quantity of the substance.

Because it is a multiple-choice question, it can be verified one by one with a set of methods.

In a, assuming that c2h4 is xmol and c3h8 is ymol, then x+y=2 2x+3y=5 2x+4y=7 can be solved with the first two equations x,y, and then substitute the third calculation result x=1,y=1 is not true, so a is wrong.

In B, assuming that ch4 is xmol and c5h8 is ymol, then x+y=2 x+5y=5 2x+4y=7 can be solved with the first two equations x,y and then substituted the third calculation result x=5 4,y=4 3 is not true, so b is wrong c assuming ch4 is xmol and c4h8 is ymol, then x+y=2 x+4y=5 2x+4y=7 can be solved with the first two equations x,y, and then substitute the third result x=1, y=1 is not true, so c is wrong.

In d, assuming that c2h6 is xmol and c3h8 is ymol, then x+y=2 2x+3y=5 3x+4y=7 can be solved with the first two equations, x,y and then substitute the third calculation result x=1,y=1 is true, so d is right, no, ask again, hope to learn and progress!!

The final result of choosing d is C5H14, and only D is consistent if you want to produce 2 kinds of gases.

The average molecular formula is.

Only d is compliant

At this time, the volume ratio of C2H6 to C3H8 is 1:1

There is a question that knows that the average formula of the gas mixture is, and because C5H8 is a gas, only option C matches the meaning of the question, and the answer is C

m(h2so4)=40*

2naoh---h2so4

mm=80*

Mass fraction of solute in sodium hydroxide solution =

It is known that 40ml of sulfuric acid solution with a density of 10% solute mass fraction happens to react completely with 50g of NaOH of a certain concentration to find the mass fraction of solute in sodium hydroxide solution.

m=vp=40*

m=2naoh--h2so4

m(naoh)=

A NaCl unit cell contains 4 NaCl ion pairs, and in the same way, a Fexo unit cell contains 4 Fexo, and it is obtained that x= This is the content of the structural chemistry section of the university.

The gas A that turns red litmus paper blue is NH3 in high school.

B can make wet blue litmus paper red, and the relative molecular mass of B is about times that of A, indicating that the relative molecular mass of B is 17, which is CO2, so A may be (NH4)2CO3 or NH4HCO3 or a mixture of both.

NH4)2CO3 = 2NH3 +CO2 +H2ONh4HCO3 = NH3 +CO2 +H2OFrom the volume ratio of NH3 to CO2 is 2:3, we can know that A is a mixture of (NH4)2CO3 and NH4HCO3, and the ratio of the amount of its substances is x:y, (2x+y):

x+y)=3:2, and the solution is x:y=1:1.

a,nh3 b,co2

a is ammonium bicarbonate or ammonium carbonate or ammonium nitrate.

Ammonium nitrate.

A is NH3, B is CO2, and A may be ammonium bicarbonate, ammonium carbonate, ammonium bisulfite.

When the volume ratio of A to B is 3:2, then A is a mixture of ammonium carbonate and ammonium bicarbonate, 1:1

I'm old, I've been in college for two years, and I can't do chemistry in high school, so I'm sad and embarrassed. --i do not know

1. Because OH- reacts with H+ at 1:1, H2SO4 contains more H+, and hydrochloric acid is as much as acetic acid, so B A=C

2. Because acetic acid is a weak acid and can only be partially ionized, when it wants to ionize as much H+ as hydrochloric acid, the concentration of acetic acid required is greater than that of H+. Hydrochloric acid is a strong monobasic acid, and the concentration of H+ is the same as that of hydrochloric acid. Sulfuric acid is a binary strong acid, one sulfuric acid can ionize two H+, so the concentration of sulfuric acid is half of the concentration of H+, so when the three acids C (H+) are the same, the order of the concentration of the substance from large to small is C a B

3. Because acetic acid is a weak acid, when the concentration and volume of H+ ionized in the three acids are the same, the concentration of acetic acid is the largest, and in the process of reacting with zinc particles, due to the consumption of H+, the acetic acid in the molecular form begins to ionize again, and constantly replenishes the concentration of H+, so that it reacts with zinc particles the fastest. The H+ in hydrochloric acid and sulfuric acid is always the same, so the reaction rate is the same. Therefore, when the three acids C(H+) are the same and the volume is the same, and zinc grains with the same shape, density and mass are added at the same time, if the same volume of hydrogen gas is produced (the same condition), the relationship between the length of the reaction time is c a=b

Hope it helps

Hydrochloric acid chemical formula HCl, complete ionization, i.e., H+ in 1molHCl is 1mol acetic acid chemical formula CH3COOH, incomplete ionization is H+ in 1molHCl, chemical formula H2SO4 in 1molHCl, complete ionization, H+ in 1molHCl is 2mol1, even if the substance is incompletely ionized because of consumption, it will be gradually ionized, that is, the total amount of H+ contained in HCl and CH3COOH is the same, and H+ in H2SO4 is the same volume, The amount of the same substance is twice the concentration of the other two substances.

2. When the three acids C(H+) are the same, it is assumed that XMOL is required, HCLXMOL, H2SO4X 2mol, and CH3COOH is more than XMOL due to incomplete ionization

3. The reaction rate depends on the concentration, because C(H+) is the same, and CH3COOH is not completely ionized, and will be gradually ionized in the reaction, so that C(H+) in the latter CH3COOH is greater than the other two.

Let's start with the first question. The energy of the reactant or product refers to the energy that the molecules of such a substance have on average, not the energy exchanged between the chemical bond formation breaks. This energy includes the potential energy between atoms, the kinetic energy of molecules, the potential energy of reeds, and so on.

Generally speaking, the greater the bond energy, the lower the material energy and the more stable it is. The lower the energy of the substance, the more stable it is. Is this clear?

This brings me to the second question. This question is not very conclusive, because there are too many theoretical loopholes in high school, and there are many counterexamples from a micro perspective or macro laws. Generally speaking, in this case, A is less reducible than B.

It can be explained this way. If the A ion has strong oxidation, then it is easy to get electrons to be reduced and it is relatively easy to lose electrons with withering, that is, the reduction of strong oxidation is weak. Of course, this is not necessarily, and it depends on the specific reactants.

The more reliable method for comparing oxidation is based on the redox equation in which the oxidation of the oxidant is stronger than the oxidation of the oxidation product, and the reducing agent is stronger than the reduction product. However, this law can sometimes be contradictory as the reactants change. So there is no satisfactory explanation for this question, and it is generally not compared in this way.

Item A: Dilute nitric acid is oxidizing, which makes the sulfur element exist in the form of sulfate.

Item b: The number of hydrogen atoms is not conserved, and the coefficient of water should be increased by 2.

C: Aluminum hydroxide cannot be dissolved in the weak alkali "ammonia", so metaaluminate will not be formed in ammonia.

Item D: Correct.

Option A you should be, dilute nitric acid has strong oxidation, the generation should be sulfate, option B equation is not flat, the number of hydrogen is wrong, option C aluminum ions and ammonia water to generate aluminum hydroxide precipitation, without further reaction, because aluminum hydroxide can react with a strong base to form metaaluminate, but it does not react with a weak base, ammonia is a weak base.

The next homework helps, and there is no trouble in doing the questions.