High school chemistry, please write the reason. minghang11

The answer is that DA carbon dioxide gas is introduced into a small amount of sodium phenol solution and an excess of sodium phenol, respectively, and the products are both phenol and sodium bicarbonate.

b Sulphur is burned in excess air and oxygen, respectively, and the products are sulphur dioxide (catalysts are required for sulphur dioxide to produce sulphur trioxide).

c Iron is burned in a small amount of chlorine and excess chlorine respectively, and the products are all ferric chloride (excessive iron does not react with ferric chloride in the solid state).

d Chlorine gas and sodium hydroxide dilute solution react to form sodium chloride, sodium hypochlorite and water.

Chlorine and sodium hydroxide concentrate hot solution react to produce sodium chloride, sodium chlorate and water.

Select D analysis for this question].

A, all generate NaHCO3, because HCO3- ionization degree is not as good as phenol, it is impossible to generate Na2CO3

B, theoretically speaking, all SO2 is generated, but in the oxygen reaction, if there is too much oxygen, it is possible to generate a small amount of SO3

c, FeCl3 is generated, regardless of the excessive amount.

D, at room temperature, the products are NaCl and Naclo, and NaCl and NaClO3 are generated under heating conditions.

Therefore, choose D to be satisfied

a Carbon dioxide gas is introduced into a small amount of sodium phenol solution and an excess of sodium phenol, respectively. The reaction products are identical. Because phenol is acidic between carbonic acid and bicarbonate, only NaHCO3 is generated, regardless of the amount of carbon dioxide

b Sulphur is burned in excess air and oxygen, respectively. The reaction products are identical. Both generate SO2In the absence of a catalyst, sulfur dioxide does not react with oxygen.

c Iron is burned in small amounts of chlorine and excess chlorine, respectively. The reaction products are identical. Because chlorine is very oxidizing, it oxidizes iron to the most.

d Chlorine gas reacts with sodium hydroxide solutions of different concentrations and temperatures. The reaction products are not the same. Sodium chloride and sodium hypochlorite are generated at room temperature. Sodium chloride and sodium chlorate are formed at high temperatures.

2mno4- +5h2o2 + 6h+ =2mn2+ +5o2 + 8h2o

The reaction can be flanked by adding 2H2O2=2H2O +O2 and its integer multiples on both sides of the equal sign; You'll find that it's all balanced.

However, only the above 2mno4-:5h2o2 is correct.

Mn from +7 +2, get 5 electrons;

In H2O2, O is -1 valence, which can be redox by itself, but in a strong oxidant environment, 2 -1 valence O atoms will all be oxidized to 0 valence O atoms to form O2

For H2O2, 2 electrons need to be lost and the O atom changes from -1 valence to 0 valence.

Therefore, the relationship between mno4- and h2o2 should be 2:5.

Precipitate Fe(OH)3 Fe(OH)2 A(OH)3

Begin to precipitate. Completely precipitated.

3) In actual production, Reaction II often introduces O2 at the same time to reduce the amount of NaNo2, and if the O2 involved in the reaction has L (standard condition), it is equivalent to the amount of Nan2 saved.

The function of nano2 is to oxidize Fe2+ to Fe3+, Fe2+ +NO2- +2 H+ = Fe3+ +NO+ H2O

4 fe2+ +o2 + 4 h+ = 4fe3+ +2 h2o

l O2 oxidizes 2 mol Fe2+

Similarly oxidation of 2 mol Fe2+, 2 mol NO2- is required

The second question is that because the ferrous hydroxide produced is very unstable and can be easily oxidized to iron hydroxide, you may only see reddish-brown iron hydroxide precipitation in the actual test.

Hope it helps.

Thank you for adopting.

1) It is related to the size of the radius.

a is on the left side of b with the same period.

c is below a congener.

The number of electrons in the outermost shell of the c atom is 4 times the number of electrons in the outermost shell of the d atom.

And because the outermost shell has a maximum number of 8 electrons

So the number of electrons in the outer shell is 8 or 4

c is at the bottom left of b, so the outermost number of electrons is 4

So C is Si (Silicon) and A is C (Carbon).

c The number of protons in the nucleus is equal to the sum of the number of protons in the nucleus of a and b.

b is o (oxygen).

D is the position of the Na2)C element in the periodic table for the third period of group IVA.

3) H2O>CH4> SIH4

4)co2 na2o2

5)naoh al(0h)3+naoh ==naalo2 + 2h2o

The answer is, in order: carbon, oxygen, silicon, and sodium.

The third cycle is the fourth main family (four in Roman numerals iv).

o>c>si> sells spine sheds

Naoh al(OH)3+NaOH= naalo2+2 H2O

First of all, the gas is colorless, the chlorine is yellow-green, and the nitrogen dioxide is reddish-brown, so it cannot be present.

Nitric oxide and oxygen produce nitrogen dioxide is reddish-brown, so nitric oxide and oxygen cannot coexist, and because there is reddish-brown gas in the air behind it, there is carbon monoxide and no oxygen.

And can make magenta fade, chlorine dissolves in water to generate hypochlorous acid and sulfur dioxide, but chlorine has been eliminated, so it can only be sulfur dioxide.

2.Of dilute sulfuric acid and dilute nitric acid, only dilute nitric acid can react with copper. The sulfate, nitrate, and H+ in the solution exist in ionic form, and all H+ can participate in the reaction in the solution with nitrate.

There are a total of moles of h+

4hno3+cu=cu(no3)2+2no2+2h2o

Therefore, moles of copper ions can be obtained, so the concentration of copper ion type is sold as.

3.First of all, the molar copper completely reacted and completely became molar copper nitrate, and there were molar nitrate residues in the molar copper nitrate.

A gas is generated, i.e., a mixture of molar nitric oxide and nitrogen dioxide, but each gas molecule contains only one n atom, so there are n atoms.

The amount of concentrated nitric acid reaction is equal to the amount of nitrogen atoms, i.e., moles of gas plus moles of copper nitrate.

4.Baking soda cannot be used. Both sulfur dioxide and sulfur trioxide react with baking soda.

Sulfur trioxide is a solid, sulfur dioxide is a gas, and there is no need to remove impurities. Furthermore, the production of sulphur trioxide is complex and is not available in the laboratory???

There are hydroxide ions in this solution, and the Mg2+ in A is precipitated when it meets hydroxide ions.

In b, hydrogen ions react with hydroxide ions to form water.

Option B is analyzed as follows:

When all are dissolved, there is Al3+, Cu2+, Fe2+, and a possible excess of H+ in the solution (no need to analyze whether it is excessive).

The addition of NaOH solution should give the most precipitate to the precipitate, indicating that Al3+ completely becomes Al(Oh)3 and is not dissolved, the other two precipitates are Cu(Oh)2 and Fe(Oh)3, and the possible excess H+ will be neutralized before the precipitate is generated.

Therefore, the amount of hydrochloric acid added at the beginning is equivalent to the amount of NaOH solution added later, so c(HCl)=c(NaOH)*v(NaOH) v(HCl)=

Because Cl- and Na+ are 1:1 reactions. In fact, it is the reaction of HCl and NaOH, so that NaOH is HCl, that is, the concentration is 1Moll-

1b Hydroxide is a solid substance, while the other three can exist in the air.2b By saturating the NaHCO3 solution, SO2 and NaHCO3 will react to form CO2 to achieve the purpose of removing SO2.

3c Only hydrochloric acid does not react with glass.

4B CO2 does not react with calcium chloride.

5D Ammonia reacts with water to form ammonia, which is alkaline.

6C In acidic solution, NO3- has strong oxidizing property and can react with copper for 7d The phenomena are: formation of precipitation; generation of precipitates and gases; Gases are generated.

8b is acidic and oxidizing.

a False. b Deliquescence is a physical effect with no chemical change.

c Error is the result of multiple processes, and dissolution is wrong if it is attributed to a single cause.

d right. The dissolution of matter, on the one hand, is the solute of the particles of molecules or ions to overcome their own attraction to each other.

Gravitational force is required to prevent the solute from leaving, and on the other hand, the dissolved solute to diffuse throughout the solvent.

Energy is consumed, so when the substance is dissolved, it absorbs heat. During the dissolution process, the reason for the temperature drop is that.

This. During the dissolution process, the particulate molecules or ions of the solute are dispersed into the solvent not only after separating from each other.

In the same time, the solute particles dissolved in the solvent can also form solvent conversions with the solvent molecules.

If solvents. If it is water, hydrate is formed). In this process, heat is released.

The aqueous solution of carbon dioxide is a weak acid solution and becomes acidic, while aluminum ions can only promote mutual hydrolysis with the weak acid groups in the strong base and weak acid salts, but cannot interact with the acid groups in the weak acid solution.

The double hydrolysis reaction refers to the mutual promotion of hydrolysis by weak acid ions and weak base cations.

Aluminum ions are introduced into the aqueous solution of carbon dioxide, and carbon dioxide meets water to form carbonic acid, but carbonic acid is unstable and quickly decomposes into water and carbon dioxide, which cannot exist in the form of weak acid ions, so double hydrolysis cannot occur.

First of all, the hydrolysis reaction of aluminum ions will form an aqueous solution of carbon dioxide when carbon dioxide is released, how can it react with the aqueous solution of carbon dioxide.