The principle of chemical production is wrong, and the following statements about chemical productio

Reason for choosing D2342: sodium added to saturated magnesium chloride solution will not undergo a displacement reaction, but sodium first reacts violently with water to form sodium hydroxide and hydrogen gas, and sodium hydroxide dissolved in water will form white flocculent magnesium hydroxide with magnesium chloride (this is the same as the sodium tried to react with copper sulfate in class).

3. Since most of the aluminum in the earth's crust occurs in the form of alumina (bauxite), aluminum is made by electrolytic alumina in industry, and electrolytic aluminum chloride will produce chlorine toxicity.

4. The blast furnace is burned and exothermic, but carbon monoxide and iron, carbon dioxide and carbon react to absorb heat, otherwise the blast furnace will burn out if it does not absorb heat and only releases heat.

D 2: Sodium is too active to replace mg

3: The raw material is alumina.

4: Heat at the beginning to initiate the reaction.

The most important point.

It is unreasonable not to give points.

1 pair. 2 false. Sodium reacts with water in magnesium chloride solution to form sodium hydroxide, which in turn reacts with magnesium chloride to form magnesium hydroxide and sodium chloride.

3 False. Aluminium chloride is a covalent compound, and elemental aluminium cannot be prepared by electrolysis.

4 false. Combustion is an exothermic reaction, and an exothermic reaction means that the total energy of the reactant is higher than the total energy of the product, regardless of the reaction conditions, the former is a microscopic understanding, while the latter is a macroscopic understanding. Therefore, choose D

Summary. The general process of chemical production can be summarized as follows: chemical raw materials--- various pre-treatments (crushing, impurities, mixing) - chemical processing--- various post-treatments (extractions) - chemical products.

There is a chemical reaction in the production process, must it be chemical.

Hello, there is a chemical reaction in the production process, which is not necessarily chemical.

Many food industries also have chemical reactions.

Like polysaccharides as well as proteolysis.

There is also the fermentation of flour.

But none of this belongs to the chemical industry.

Under the condition of no high temperature and high pressure, a little sulfuric acid is added to the solid finished product and diluted into a liquid similar product, which belongs to the chemical industry.

This belongs to the chemical industry.

The general process of chemical production can be divided into: chemical raw materials--- various pre-treatment (crushing, impurity removal, mixing) - chemical processing--- various post-processing (extraction) - chemical products.

a. There is no new substance generation in alcohol volatilization, which is a physical change, so the option is wrong;

b. Starch is digested into glucose, which is a new substance and belongs to chemical changes, so the choice is correct;

c. There is no new substance generation in the blanket made of wool, which is a physical change, so the choice is wrong;

d. There is no new substance generated when iron is cast into an iron pot, which is a physical change, so the option is wrong; Therefore, choose B

b. The ammonia synthesis reaction is a reversible reaction!

c.Then the iron pipe is galvanized, and the iron pipe is used as the anode, and the zinc block is used as the cathode. It's the other way around.

I choose AC.

a.Sulfuric acid is prepared by reacting sulfur trioxide with water, and nitric acid is prepared by reacting with water with NO2.

so3+h2o=h2so3

3no2+h2o=2hno3+no

b.That's right. nch2=ch2—catalyst -[ch2-ch2—]-ncError, h2 cannot restore al2o3.

The method of smelting metallic aluminum is electrolytic molten alumina. 2al2o3 = energized = 4al+3o2

d.That's right. N2 + 3H2 = high temperature, high pressure, catalyst = 2NH3

Hengqing 1) pure banquet alkali.

Xiangxu 2) H+

oh - h 2

o；2h + co 3

co 2 +h 2o

1) Pure Noise Alkali Shengkai and Sun Pai (or Na2CO32) CO3

2h + co 2

h 2 o、h +

oh - h 2

o 3)ab

4) NAOH and NA2

co 3 na 2

CO3 and NAHCo 3