In a high school competition, how to determine whether a reaction containing nitrogen is a reaction

If the volume is 1L, then the amount of ammonia = 1L

mol, the volume of ammonia is equal to the volume of ammonia solution, so the amount concentration of ammonia = 1mol1l

The amount of nitrogen dioxide is 3mol, and the reaction occurs: 3NO2 + 2H2O = 2HNO3 + NO, and according to the equation, the volume of the solution is 2 of the volume of nitrogen dioxide

3, so the volume of the solution = 2

3 3mol, the amount of nitric acid = 2

3 3mol = 2mol, so the concentration of nitric acid = 2mol =, so c

1 mole of silicon tetrachloride reacts: SiCl4 + 2H2 = Si + 4HCl

To break a 4 molar Si-Cl bond and a 2 molar H-H bond, a 4 molar H-Cl and 2 molar Si-Si bond is generated (each back Si and another 4 Si atoms share 4 Si-Si bonds, So.

Answer: The number of Si-Si bonds per silicon atom is 4 2 = 2, and the Si-Si bonds contained in each mol of Si are 2 mol).

h = 4*431 + 2*176 - 4*360 - 2*436 = - 236

A. Ammonia (NH3

It can be liquefied into liquid ammonia at atmospheric pressure, so liquid ammonia is composed of a molecule of ammonia molecule, which is a pure substance, so the statement A is correct;

b. Since liquid ammonia can be used as a clean fuel for automobiles, it shows that liquid ammonia is flammable, so B is correct;

c. The oxygen atoms in the reactant molecule are 6 skins, and the product molecule is also 6 oxygen atoms, so there should be no poor aerobic elements in x, so C is wrong;

d. The reactant molecule contains 4 nitrogen atoms, 12 hydrogen atoms, and 6 oxygen atoms, and the product molecule already contains 12 hydrogen atoms, 6 oxygen atoms, and 4 nitrogen atoms are missing, because the coefficient in front of x is 2, so the chemical formula of x is n2

Therefore D is correct

Therefore, c

Ammonia gas is produced when liquid nitrogen and hot water are combined because liquid ammonia has a low boiling point and volatilizes when heated. Liquid nitrogen is inert, colorless, odorless, non-corrosive, non-flammable, and has extremely low temperatures.

Nitrogen makes up the majority of the atmosphere (volume ratio, weight ratio. Nitrogen is inactive and does not support combustion; But it is not a necessary element to sustain life.

In general, nitrogen is inactive. When heated to very high temperatures, it reacts with more reactive metals such as lithium and magnesium to form nitrides. It also reacts with oxygen to form nitrogen oxides, and when a catalyst is present, it reacts with hydrogen to form ammonia.

Liquid nitrogen absorbs heat sharply and expands to form a large amount of gas, causing **.

Due to the rapid cooling and solidification of molten steel, it will form a falling shape (droplet-shaped?). There is a quenching technique in the industry: the strength of the metal is greatly increased by rapid cooling, but it is not known whether it will be broken here.

Due to the influence of high temperatures, liquid nitrogen will rapidly vaporize and expand rapidly, and if it is in a limited container, then ** is unavoidable. Think about the opposite: what if you pour a small amount of water into the hot oil?

You can do experiments, but I'm not responsible for safety.

Just use the water directly.

The solubility of 1:700 is not covered.。

No, if the amount is not large, it can be absorbed with water.

Hydrogen. According to the law of conservation of mass, the type of element does not change before and after the reaction, and the number of atomic types does not change. Because the ratio of the number of nitrogen and oxygen atoms in liquid ammonia NH3 is 1:

3. The ratio of the number of nitrogen and oxygen atoms in the generation of sodium amino is 1:2, so the other product must contain hydrogen atoms. Hydrogen is an elemental substance made up of hydrogen atoms.

Next week, our teacher will talk about this question, and I'll see if there are any deficiencies in what I have written, and I'll make up for it.

(1) In the laboratory, Cu is used to react with concentrated sulfuric acid and concentrated nitric acid to prepare and collect SO2 and NO2, regardless of the convenience of controlling the reaction, the instrument containing concentrated sulfuric acid and concentrated nitric acid should use a separating funnel, so the gas generating device should be selected B; The density of SO2 and NO2 is greater than that of air, so it needs to be collected by the downward exhaust air method, and the collection device needs to be selected C; Regardless of the prevention of backsuck, F should be used for the complete absorption device, so the answer is: BCF;

2) 1molSO2 is introduced into the solution containing 1molNaOH to react completely, and the two react to form NaHSO3;

Due to HSO3

The degree of ionization is greater than the degree of hydrolysis, then the solution shows acidity, so the answer is: NaHSO3; hso3

The degree of ionization is greater than the degree of hydrolysis;

3) Some properties of liquid ammonia are similar to those of water It is known that water molecules can self-ionize by themselves, and the anions and cations generated contain 10 electrons, and the two ions are: NH4

NH2, then the equation for self-ionization of liquid ammonia molecules: 2NH3?nh4

nh2；Liquid ammonia reacts with NA to form NANH2 and hydrogen, and the chemical equation of the reaction is: 2NA+2NH3 2NANH2+H2, so the answer is: 2NH3?nh4

nh2；2na+2nh3═2nanh2+h2↑；

4) a by NH3?h2o?oh-+nh4

It can be seen that c(oh

?c(nh+4

c(nhho)

It is an equilibrium constant, which changes with temperature, and its value does not change after dilution with water, so a is correct;

b by NH3?h2o?oh-+nh4

It can be seen that when water is added to promote ionization, then n(nh3?H2O) decreases, N(OH-) increases, C(NH

ho)c(oh?)

decrease, so B is wrong;

c．c（oh-）?The product of c(h+) is the ion product of water, and when diluted with water, the temperature does not change, then the product of c(h+) and c(oh-) does not change, so c is correct;

d After dilution of ammonia, the concentration of hydroxide ions in the solution decreases, and the concentration of hydrogen ions increases, c(h+).

c(oh?)

The value of is increased, so d is wrong;

So the answer is: a c;

5) (NH4) 2SO4 decomposition products in strong heat are SO2, N2, NH3 and H2O, ammonium ions generate N2, generate 1mol N2 and lose 6mol electrons, sulfate ions generate SO2, the valency decreases by 2 valence, according to the conservation of electrons, the amount of substances that generate carbon dioxide at the same time when generating 1mo nitrogen is: 6mol

2=3mol, so the answer is: 3