High School Chemistry Questions on Elemental Properties. Find detailed reasons and ideas for solving

1) According to the reaction of acidic oxides and alkaline oxides to generate oxygenates in the corresponding valence state, it can be seen that 3Na2O+As2O5=2Na3ASO4, because in AS2O5 AS is +5 valence, in NA3ASO4 is also +5. Replace O with s to get the result 3Na2S + As2S5 = 2Na3Ass4.

According to 2Na2O2 + 2CO2 = 2Na2CO3 + O2. By substituting S for O, we know that 2Na2S2+2Cs2=2Na2Cs3 + 2S, so Na2S2+CS2=Na2Cs3 + S

The first null note that the valency is not the same, because there is no oxidizing agent and reducing agent.

The second void should pay attention to the analogy of peroxide, so there is obviously a disambiguation here

This kind of question, just bring it directly

What is this like, sodium sulfide can be regarded as sodium oxide, because they are basic sulfide and basic oxide respectively. Carbon disulfide can be regarded as carbon dioxide because they are acid sulfides and acid oxides, respectively. Carbon dioxide and sodium oxide can be directly combined to form sodium carbonate, and sodium sulfide and carbon disulfide can be synthesized into sodium thiocarbonate (Na2CO3) by analogy.

The same goes for the first question, hope

1.The metallic element that reacts most violently with water: CS

2.The element with the largest atomic radius: xe

3.The most reactive metallic element: CS

4.The most ** oxide hydrate is the most alkaline element: CS5Non-metallic elements that react most violently with water: f

6.The most stable element that forms gaseous hydrides: f

7.The most reactive non-metallic elements: f

8.There is only a negative element without a positive valence: f

9.Non-metallic elements without oxygenated acids: f

10.Elements of non-oxidic acid that can corrode glass: f

11.The most stable element of gaseous hydride: f

12.Element with the weakest anionic reduction: f

13.Elements that form the largest variety of compounds: c

14.The element with the highest elemental hardness: c

15.The element with the largest mass fraction of hydrogen in gaseous hydrides: C16Positive and negative valency algebra and zero elements: c si17The lightest element: H

18.Element with the smallest atomic radius: h

19.One of the isotopes has only a child in the nucleus of an element without neutrons: h20An element with equal atomic number, electron shell, and unpaired electron number: h21The most abundant element in the earth's crust: O

22.The element with the highest boiling point in gaseous hydrides: O

23.Gaseous hydride is an element that is liquid at room temperature: o

24.The most abundant element in the air: n

25.The aqueous solution of gaseous hydride is an element that is basic: n

26.Gaseous hydride and the most ** oxide hydrate can be combined with the element that reacts: N27

The element in which gaseous hydride and the most ** oxide hydrate can cause redox reactions: S28Gaseous hydrides and oxides can react at room temperature to form elemental elements of this element:

s29.The most abundant metallic element in the earth's crust: Al

30.The most ** oxide and its hydrate are amphoteric elements: AL ZN31The most susceptible non-metallic elemental elements to ignition: p

32.The lightest metallic element: li

33.Elemental metal element in liquid state at room temperature: Hg

34.Elemental non-metallic elemental in liquid form: BR

35.The element that reacts to the yellow color of the flame: na

36.Flame reactive purple element: k

38.The element with the largest atomic radius in a noble gas: xe

39.The most ** oxide is the most acidic element for hydrates: Cl40A short-period element that can react with water and release gas at room temperature: F Na

According to the title, if the outermost number of electrons of the y atom is 3 times the number of electrons in the inner shell, then the number of electrons in the inner shell cannot exceed or equal to 3, but can only be 2Then the number of electrons in the outer shell is 6, and because these elements are short-period elements, therefore, Y is the No. 8 element oxygen O, then Z is sulfur S, X is nitrogen N, and W is chlorine Cl. Therefore, you can judge the options one by one:

Option A, the hydride of X is ammonia NH3, and the hydride of Y is water H2O, so this sentence is not rigorous and wrong at the same time; Option B, the most ** oxide of W is HCO4, which is very acidic, and the oxidation is also very strong, and the most ** oxide of Z is H2SO4 sulfuric acid, but this sentence is not too rigorous, if it is to be stronger than the acidity, the concentration of the acid must be limited to the same, there is no here, if the concentration is the same, the acidity of perchloric acid (HCO4) is stronger than that of sulfuric acid; Option C, Z is sulfur, Y is oxygen, so option C is wrong, option D, the compound formed by X and Y is nitrogen oxide, there can be many of the following, NO, NO2, N2O3 ......These are gases, and some things are insoluble in water, such as nitric oxide, so option D is also wrong, so this student, you can think about the answer to this question again. I also hope that my answer can help you and be used by you.

The number of outermost electrons of the y atom is 3 times the number of electrons in the inner shell, then y is 'o'. x is "n". z is "s.""。w is "cl".

A: NH4 is not more stable than H2O.

The hydrate corresponding to the most ** oxide of B W is HCO4, which is more acidic than H2SO4.

c Look at the periodic period of the elements.

The compounds formed by D x and Y have NO, NO2, and NO, which are insoluble in water!!

The focus of each grade of high school is different from that of the college entrance examination. The first year of high school is mainly basic experiments and halogens and alkali metals, and the second year of high school is more learned, organic matter, chemical experimental principles, crystal structure of the periodic table, etc. The question type of the college entrance examination is fixed, but there are many knowledge points, a large span of front and back, a solid and careful foundation, and the test of 80 is okay.

Aluminum, iron, copper, plus the first and seventh main families.

1.Aluminum, amphoteric elements, and acids and bases can be reacted to form hydrogen.

2.Aluminum hydroxide, reacts with strong acids and bases.

3 chlorine water, three molecules, four ions. Acidic, oxidizing, bleaching4Sulfur dioxide, acidic, oxidizing, reducing, bleaching 5 concentrated sulfuric acid, acidic, oxidizing, dehydrating, absorbent.

6. Ammonia, highly soluble in water, fountain experiment. Alkaline gas, reducible.

7. Bromine water, to test the unsaturated bonds, oxidation, and sulfur dioxide reaction in organic matter.

8. Potassium permanganate acidic solution, oxidizing, testing the reducing property of organic matter.

9. Concentrated nitric acid, strong oxidation, bleaching, acid-base indicator first discoloration and then fading, so that the protein with benzene ring is yellow first and easy to decompose.

10. Sodium peroxide, strong oxidizing, bleaching, oxygen production.

There are many more, first so many, the phone typing is very crashing.

2）s::c::s

3) CH2 = CH2 (ethylene).

4）c4n4

5) H2CO3(H2CO3 Hno3 H2SO4)(6) 2Hno3+H2S=2H2O+S +2NO2 Inference Process:

The atomic numbers of the short-period main group elements r, x, y, and z increase sequentially, and occupy three short periods respectively (1-3 periods are short periods), and x,y are located in the same period and are adjacent to each other, then r is the main group element of the first period (i.e., h element), x,y is the main group element of the second period, and z is the main group element of the third period.

The highest positive price of x is equal to the absolute value of the lowest negative price, x is the c element, y is adjacent to it, and y is the n element.

The number of outermost electrons of the Z atom is equal to 2 times the number of electrons (3), and the number of electrons in the outermost shell is 6, so Z is an element S.

Oxygen second cycle VIA group.

na+11）2）8)1

na>s>o

hclo4 (lowercase 4 after oxygen).

naohoh- +h+ =h2o, hope it helps.

The four elements of the short period belong to 3 periods, so r is the hydrogen element, x, y are the same period, the highest positive valence of x is equal to the absolute value of the lowest negative valence, x is the carbon element, y is adjacent to it, and y is the nitrogen element. z is in the third period, the number of outermost electrons is 6, so it is sulfur.

The lowest valence ions of AC are A2- and C-,, which can indicate that A is the sixth main group, possibly O or S, and C is the seventh main group. May be F, or Cl. They can only be elements of the second or third cycle.

B2+ and C- have the same electron shell structure, indicating that B is the second main group of beryllium and magnesium, and because it has the same electron shell structure as C, then it can only be magnesium. Because beryllium ions have 2 electrons.

Judging by this, b, magnesium. 12 Then, c, fluorine 9, so, a is oxygen 8

A is NH4NO3 N (nitrogen).

b is 0 (oxygen).

c is p (phosphorus).

d is li (lithium).

1) (There is a problem, the question does not define the valency of n elements) N2O5 N2O3 etc.

2) 2Li + 2H2O ===2LiOH + H2 (3) Stability NH3 is greater than ( )PH3

If you have a bounty, I'll tell you.

I choose ぀Since it is converted into Cus by Zns or PBS, Cu2+ +Zns=Cus+Zn2+, according to the definition of precipitation dissolution equilibrium, it is converted from large solubility to small solubility, so the solubility of Cus is less than the solubility of PBS, A is wrong.

b.It can be inferred from the first sentence in the question stem: the sulfide of the primary copper on the surface of nature is oxidized and leached into CuSO4 solution.

The sulfides of primary copper are reducible, but it cannot be proven that copper blue (Cus) is not reducible. The S element in CUS is -1 valence, which is most easily oxidized to S elemental matter (0 valence), and can also be oxidized to +6 valence when encountering extremely strong oxidants such as concentrated nitric acid, so B is wrong.

c.As explained in a, Zns is a difficult insoluble substance, so it must not be taken apart when writing the ion equation, so the equation is written incorrectly.

d.From the first sentence in the question stem: the sulfide of the primary copper on the surface of nature is oxidized and leached into Cuso4 solution, and it can be seen that the oxidation reaction occurs in the whole process, and according to the equation in option B:

Cu2+ +Zns=Cus+Zn2+, we can see that the metathesis reaction has occurred, so d is right.

In addition, the precipitation and dissolution balance of insoluble electrolytes in option A is the content of the second semester of the second semester of high school, if you are a senior student, this option will be a bit out of the outline here, I hope my answer will be helpful to you

A, the metathesis reaction needs to be carried out in the direction of the ion concentration becoming smaller, so Cus is more difficult to dissolve than PBS, wrong.

b, cus can be ignited in oxygen to generate copper oxide, and sulfur dioxide, or reducing, wrong c, zns is insoluble, to write into molecular form, wrong.

So choose D, D is right.