Who s going to solve my chemistry problem?

The answer to the first question is wrong, you should choose B, the one who chooses D is all nonsense, Al2O3 doesn't even have H, how to provide protons If you want to remove H2O in CH3CH2OH, you should add CAO first, and then distill, if you don't add CAO, because the boiling point of CH3CH2OH and the boiling point of H2O are similar, plus the influence of hydrogen bonding is easy to azeotropy, the purity of CH3CH2OH obtained is low, assuming that the amount of NO and O2 substances is 2mol, so, The amount of substances that react to form NO2 (not considering the conversion to N2O4) is 2mol, and O2 is 1mol left, and then assume that NO2 consumes 2xmol to generate XMOLN2O4, and the volume fraction is equal to the quantity fraction of the substance, so 2-2x 3-2x+x=, the solution is x=, and the mass of the mixed gas is 2*(30+32)=124g, and the sum of the amounts of substances of the mixed gas is 3-2*, so the average molar mass of the mixed gas is.

I don't know much about the first one, but if it were me, I would choose water. The second is that it cannot be distilled because ethanol has a lower boiling point than water. But it doesn't mean that the substance only evaporates when it reaches the boiling point, I guess you have the impression that water has already begun to produce water vapor before it boils.

Therefore, if you choose distillation, the water vapor will be mixed in.

It's been a long time, but I searched for the second question and saw the first question. Satisfactory answers, there are questions! If you go through the international chemistry, there is a special definition, water can indeed give and bind protons, but in the definition, water is neither an acid nor a base.

That's how people define it!! Don't mislead people, okay?

I don't know much about the first one, but I think it's both an acid and a base, and it's supposed to be amphoteric substances, and only alumina is an amphoteric compound, and the second distillation is right, but quicklime should be added during distillation to avoid bringing out water during distillation, and the third one hasn't been figured out yet.

Al2O3+ 6H+=2Al3+ +3H2OAL2O3+2OH-=2(ALO2)-+H2OH2O: Reversible H++OH- both H+ and OH- and therefore neither counts.

The acidic solution can make the purple litmus solution red, and the non-fibrous phenolphthalein does not change color.

The alkaline solution can make the purple litmus solution turn blue, and the colorless phenolphthalein turn red.

Add purple litmus to the neutral solution, and the solution is still purple, and the colorless phenolphthalein is still colorless.

To judge the acidity and alkalinity of a solution, you can use acid-base indicators such as litmus or phenolphthalein, or you can use pH test paper to measure the pH value, if it is greater than 7 is alkaline, less than 7 is acidic, and =7 is neutral.

Of course, neutral substances plus litmus and phenolphthalein do not change color, acidic plus litmus turns red, alkaline plus litmus turns blue: acidic plus phenolphthalein does not change color, and alkaline plus phenolphthalein turns red.

Acidic substances seem to start with h (for example.

hclh2so4）

The alkaline or rotten substance ending in is OH

Litmus turns red when it is acid, and it turns blue when it is alkali.

Phenolphthalein does not change color when exposed to acid (colorless in history).

It turns red when exposed to alkali.

Purple litmus solution.

1.If the test solution is red, it means that the liquid is acidic;

2.If the test solution is blue, it means that the liquid is alkaline; Letter or remainder.

3.If the group is purple, it is neutral.

Phenolphthalein. It does not change color in case of acid.

It turns red when exposed to alkali. The litmus discoloration range is between pH = . It is a weak organic acid with a relative molecular weight of 3300, which changes its conjugate structure and changes color under the different actions of acid-base solutions.

It is an acid-base indicator.

Phenolphthalein is a weak organic acid that has a colorless lactone structure in a pH solution, as a quinone structure.

The discoloration range is slippery, so phenolphthalein can only test for alkalis and not acids.

A Because CO2 reacts with Naalo2 to form Al(OH)3, it means that carbonic acid is greater than that of aluminic acid, while carbon dioxide does not react with Nagao2, so carbonic acid is not GAO3.

Strong. That's why I chose A.

2 That's not right.

Here I2 is used as a reducing agent. Increased valency. Whereas, Cl2 is a reduction product. The reduction property of Cl2 is not as strong as that of I2, that is, the metallicity is not as strong as that of I2, so the scrap metal property of Cl2 is stronger than that of I2. ~

So that's not right.

Upstairs is the positive solution, oxidant or reducing agent depends on the valence, the liter is the reducing agent, and the decrease is the oxidant. Both are the same, the reducing agent reflects the reducibility, and the oxidant reflects the oxidation.

Have you ever learned the concept of quantity of matter? If not, use the following solution:

Na is all converted to NaCl, so the mass of Na in the mixture is equal to the mass of Na in NaCl.

hcl --nacl --na

The solution yields x=, i.e., the mass of the original unoxidized Na is.

Let Na2O be Y G, and the remaining unoxidized Na is Z Gy + Z = and the mass of Na).

The mass of Na and the unoxidized Na in Y*2Na Na2O+Z= is solved to obtain Y=,Z=

i.e. Na2O is, and the mass of the oxidized Na is.

The total mass of na is.

The mass fraction of the oxidized NA is:

Let the amount of Na2O species be x, and the amount of unoxidized Na is Y62X + 23Y =

2x + y = the amount of matter = the amount of matter of cl) and then solve, get x and y, you can do it.

The first gas collected is hydrogen, which is equal to, and barium ions have.

The reaction of 2HCl+Zn---H2+ZnCl221H2SO4+BACL2=2HCl+BaSO4 consumes barium ions, and the rest reacts with Na2SO4 12 Therefore, sodium sulfate has, sulfuric acid has.

Results: The concentration of sodium sulfate was:

It's not difficult to do, but it's hard to type

It should be. The specific calculation process is as follows:

3cu + 8h++2no3－=3cu+2no+4h2o9mol 1mol

It follows that H+ is an excess, and the calculation should be based on the amount of copper or nitrate ions. From the equation, it can be concluded that 1molNO3 can be reduced to 1molNO. From this, it can be concluded that the volume of the generated no under standard conditions is approximately .

In a mixed dilute solution containing 1 mol of nitric acid and 4 mol of sulfuric acid, copper powder is added, and after a full reaction, the volume of the gas (assuming that it is all nitric oxide) under standard conditions is about ?

Write the ion equation 3Cu + 8H + 2NO3 = 3Cu + 2NO+ 4H2O, you can know the proportion of copper, hydrogen ions, and nitrate, and then according to the amount of the three substances, you can know that the hydrogen ions are the least, so it should be calculated according to hydrogen ions. 8h=2no, find the volume as, i.e., liters.

That is, C5H1O belongs to the isomer of the alkene. And it is required that there are 3 isomers when the main chain C is the same.

Answer: CH2=C(CH3)-CH2-CH3 2-methyl-1-butene.

CH3-C(CH3) = CH-CH3 2-methyl-2-butene.

CH3-CH(CH3)-CH=CH2 3-methyl-1-butene.

1.Urea is an organic substance.

2.Choose A. b. Chlorine gas meets water to generate highly oxidizing chlorine water, which can oxidize sulfite into sulfate; c. The acidity of carbonic acid is stronger than that of chlorine water, so calcium carbonate precipitation will be generated; h in d is not conserved.

3.Nitrogen dioxide is soluble in water, which is very oxidizing and oxidizes sulfur dioxide into sulfate.

The first question can be memorized when reading books, because the definition of organic and inorganic matter is very clear.

The second question, usually pay more attention to the association, in fact, they are all the same, according to the properties of various ions and reactions, and whether the elements on both sides of the equation are conserved, it is easy to make.

Question 3 is similar to question 2, it is also very simple to familiarize yourself with the properties of various ions, and then simulate the reaction process and situation according to the combination of options.

In general, it is usually more accumulation and more association

I think you should raise the bounty 、、、

1 is organic.

2 A b is wrong in the formation of sulfate C is wrong in the generation of calcium carbonate d Hydrogen is wrong.

3ACD C Nitrate oxidizes SO2 in D NO2 becomes nitric acid oxidizing SO2 in water

1.Urea is an obvious organic substance, and the initial hydrolysis of urea from the inorganic ammonium cyanate is still a major event in the chemical world.

2.Choose A. b. Sufficient chlorine gas will oxidize sulfite; c. Note that there are calcium ions in the system, and the carbon dioxide in the air can only form carbonate and then become calcium carbonate precipitation; d is not conserved.

3.Nitrogen dioxide will oxidize sulfur dioxide into sulfate in water, and as long as there is nitrogen dioxide, there will be precipitation.