CHEMISTRY OLYMPIAD QUESTIONS TEACHER GHLLZHY, PLEASE COME IN

If there is more, draw it with the molecular orbital theory, or use redox and push it yourself, what NCL5, FEI3, N3, as long as the formation of electrons reduces the energy.

1l h3 exists, and in the depths of the universe, 3l your second conclusion is wrong.

LZ, you're competing, ahh

Just studying organic chemistry.

Look for a few unstable substances that are prone to isomerization

As two carbon-carbon double bonds are attached to a carbon atom.

Or two hydroxyl groups attached to a carbon atom.

Just learn the master and don't criticize

fei3

The landlord's attitude doesn't seem to be very good, since it's all about discussing here, why use such embarrassing language to attack others.

It's like you've studied chemistry

There are a lot of people who can make it, but you don't see it

Arrogant children ask questions in a critical tone

It's simple. ag(oh)2 is not. H4CO4 is not.

It seems that there is a gas that is easily absorbed by water.

Take another 10 grams of this solution, pay attention to this.

The mass fraction of the solute in the original solution must be calculated first. First, set to x, two parts of the solution evaporate to form a saturated solution, and the mass fraction of the solute is equal.

The solubility that can be solved by x can be solved

It shouldn't be 16, I don't have a pen here, I can't count.

The first evaporation doesn't have to be a saturated solution, so it can't be used to calculate solubility.

From the question, it can be concluded that the solution is unsaturated, and it is necessary to evaporate x grams of water to make 10 grams of solution a saturated solution.

then the solution is x=..Do the math yourself.

I'm in the chemistry competition class.

1: The first one selects a lone pair of electrons, which will compress three pairs of bonding electrons, and NSP3 will be hybridized by megapixels, but due to the solitary pair, the bond angle will be less than 109 degrees 28 minutes. N in b is sp2 hybridization, 120 degrees.

N in C is also sp3 hybridized, but due to the large electronegativity of F, the electrons tend to N and the bonding electrons repel each other. More than 109 degrees 28 minutes. The same is true for NCL3, and the larger CL atoms will also repel each other, making the bond angle increase;

The central atom has empty orbitals and there are single electrons on n in d.

The first one is C, and the second one is A.

n(a):n(o)=:28/32*2=

The oxide chemical formula is in the subscript.

Is it the ratio of the quantity of matter? What is 32*2?

According to the law of conservation of mass, the mass ratio of each element before and after the reaction is unchanged.

So the mass ratio of a to oxygen element::28g=1:56

Relative atomic mass ratio of a to the oxygen element: a: 16

The ratio of a to the number of oxygen atoms: (1:56):(a:16)=2:7a, so the chemical formula is a2o7a

2,7a is the lower foot mark.

So a

Because it is a complete reaction, 1 o should get 2 electrons.

So a total of 7mol electrons are transferred.

So the valency of a is +7

So the chemical formula of this oxide is A2O7

I need to log in, I can't find the test questions, why are you sticking them out?

1, A2, P area refers to the third car main group to the eighth group of all elements, the DS area is the closed beam refers to the first subgroup of copper, silver and gold and the second subgroup of zinc, cadmium and mercury, S area refers to the first slag imitation of the main group and the second main group elements in the periodic table, so according to the title of A

1 a2 c

3 A ion change side chain verticality is the change of atoms into ions, and the properties of the beating are large.

, but you can't judge directly, you need to check the table, and Lao Hu shouldn't have it when you take the exam.

The P region is formed with 18 anion electrons, and only the S region can be disassembled. (There's something wrong with the question, and the answers to A and C are the same).

3.？Envy? I don't know.

Think about it in extreme terms.

Assuming that the mixture is all magnesium, then to generate 1g of hydrogen, the mass of the mixture needs to be x g mg + 2HCl = mgCl2 + H2

xg。。。1g

24/x=2/x

x=12gAssuming that the mixture is all zinc, then to generate 1g of hydrogen, the mass of the mixture needs to be yg Zn+2HCl=ZnCl2+H2

yg。。。1g

65/yg=2/1g

y = assuming that the mixture is all aluminum, then to generate 1g of hydrogen, the mass of the mixture needs to be z g 2al+6HCl=2alcl3+3H2

zg。。。1g

54/zg=6/1g

z=9g In summary, the mass range of the mixture is between 9g because the composition of the mixture is uncertain.

It will be the quality of the reactant.

The relationship between the generation of hydrogen is as follows:

Reactant - hydrogen.

mg：12-1

al： 9-1

I know it by the limit method.

The range is up to 9g.

The chemical formula mg 2h al 3h zn 2h is that the three metals of aluminum, magnesium and iron react with hydrochloric acid respectively, and the masses of magnesium, aluminum and iron are 12g and 9g respectively to produce 1g of hydrogen.

Then in the case of a mixture, the mass range of this mixture is 9 using the limit analysis method.

Remember to give points, thank you! ）

The quality of the mixture is not known, and the quality of hydrochloric acid is not known, how to calculate?

Even if it might be, there should be a range of possibilities