One reagent that can be used to identify iron powder, charcoal, copper oxide, manganese dioxide is

Sulfuric acid can be phenomena gas that does not react with blue solution (heated) flesh-colored solution.

Dilute hydrochloric acid can be phenomena of gas not reacting with green solution (heated) flesh-colored solution.

Concentrated hydrochloric acid can be phenomena of gas without reacting with green solution (heated) chlorine gas.

Chlorine water is not good, there is no phenomenon.

It is concentrated hydrochloric acid A that reacts and the solid disappears and the solution turns blue

When B+ is hot, bubbles are generated, light green gas is generated, and the gas comes into contact with the wet blue litmus paper, which is red first and then fades (proving that there is chlorine gas and reacts with Mno2).

c There are bubbles produced The liquid side is light green, and the solid is dissolved.

dThere is no obvious phenomenon

The answer should be C, not DBecause copper oxide reacts with hydrochloric acid to become a blue solution, carbon does not react with hydrochloric acid and does not change.

cuo+2hcl=cucl2+h2o

D Error, copper oxide and charcoal powder do not react with copper sulfate, and a error cannot be identified because charcoal powder and copper oxide are both black.

b False, because neither charcoal powder nor copper oxide are soluble in water.

Answer: Ccuo+2HCl=CuCl2+H2O CUO reacts to dissolve, while charcoal powder does not.

a.The colors are all black.

b. It is not soluble in water.

Neither D nor cuso4 reacts.

A dilute sulfuric acid does not react with charcoal, reacts with iron to produce gas, reacts with manganese dioxide to form purple (when the concentration is high) or flesh-colored solution (at low concentration), forms a blue solution with copper oxide, and forms a light green solution with ferrous oxide and will turn into a yellow solution.

Dilute sulfuric acid: dilute sulfuric acid reacts with copper oxide to form a blue solution, copper sulfate (copper ions are blue), dilute sulfuric acid reacts with manganese dioxide to form manganese sulfate into a purple solution (manganese ions are purple), and dilute sulfuric acid reacts with iron to produce gas (hydrogen).

Dilute sulfuric acid does not react with carbon, and there is no obvious phenomenon!

C-sulfur powders

Iron Fe metal copper cu

Oxygen O2 nitrogen N2

Helium He2 Hydrogen H2

Sodium Na Silver AG

Gold au magnesium with mg

Calcium, CA aluminum strips, al

Zinc Zn lead PB

Hg chlorine Cl2

Water H2O, ferric oxide, Fe2O3

Carbon monoxide CO

Manganese dioxide mnO2

Sodium chloride NaCl

Silver chloride AGCL

Sulfur trioxide SO3

Ferric tetroxide Fe3O4

Magnesium oxide MGO

Calcium oxide cao

Copper oxide. Phosphorus pentoxide.

Aluminium oxide.

Sulfur dioxide. Potassium chloride.

Potassium permanganate. Potassium chloride.

Potassium manganate. Peroxide destroys laughing hydrogen.

Neon. Argon.

Red phosphorus. Crystalline silicon.

Nitrogen dioxide. 2 molecules of carbon dioxide.

The most abundant element in the air (nitrogen).

3 iron atoms.

2 hydrogenophores containing molecules.

The most abundant element in the earth's crust (oxygen).

Silicon dioxide. Magnesium ions.

2-valent magnesium.

2 magnesium ions.

Sodium ions. Ruriko.

Zinc ions. Potassium ions.

Calcium ions. Oxygen ions.

Chloride ions. Aluminium ions.

Copper ions. Hydroxide ions.

Ammonium (disturbing an) root ions.

Sulfate ions.

Carbonate ions.

Nitrate ions.

Iron ions. Ferrous ions.

Hydrogen ions. Silver ions.

Barium ions. Sodium hydroxide.

Potassium hydroxide. Copper hydroxide.

Barium hydroxide. Magnesium hydroxide.

Iron hydroxide. Ferrous hydroxide.

Calcium hydroxide. Aluminum hydroxide.

Nitrate. Sodium nitrate.

Magnesium nitrate. Potassium nitrate.

Copper sulphate. Magnesium sulfate.

Iron sulfate. Ferrous sulphate.

Magnesium chloride. Calcium chloride.

Aluminium chloride. Barium chloride.

Zinc chloride. Ferrous chloride.

Barium sulfate. Aluminum sulfate.

Sodium oxide. Copper oxide.

Calcium carbonate. Barium carbonate.

Sodium carbonate is speechless, it's too much. Let's fight again next time.

Analysis】 Iron is a metal element, and the fiber wheel is ranked in front of hydrogen in the metal activity order table, and can have a displacement reaction with acid; Copper oxide is a metal oxide, which can react chemically with acid, and Naiyou carbon powder is a non-metallic element, which generally does not react with acid at room temperature. Therefore, as long as dilute sulfuric acid or hydrochloric acid is used, the mu letter can be destroyed to distinguish them. Add dilute hydrochloric acid or dilute sulfuric acid, the bubble is iron powder, the black powder is dissolved, the solution is blue after the reaction, copper oxide powder, and there is no obvious phenomenon of carbon powder.

Comments] This question examines how to select identification reagents. The general rule of solving this kind of problem is: if the identified substances are metal element, non-metal element and metal oxide, strong acid (generally dilute sulfuric acid and hydrochloric acid) can be used as the reagent for identification.

Test Topic: Identification and Inference of Substances Chemical Properties of Metals Special Topic: Identification of Substances Analysis:

a. Charcoal and dilute sulfuric acid can not react, copper oxide and dilute sulfuric acid reaction can obtain blue copper sulfate solution, iron powder and dilute sulfuric acid reaction can obtain light green ferrous sulfate solution and release hydrogen at the same time; b. Charcoal and copper oxide can not react with copper sulfate solution, and iron powder can react with copper sulfate solution to obtain copper and ferrous sulfate solution; c. Charcoal, copper oxide and iron powder cannot react with sodium hydroxide solution; d. Charcoal, copper oxide, and iron powder cannot react with water a. Put charcoal, copper oxide, and iron powder into dilute sulfuric acid, and there is no obvious change for charcoal; The black solid dissolves, the solution becomes blue, and the black solid is copper oxide; The black solid is dissolved, the solution is light green and there are bubbles, and the solid is iron powder; Therefore, the use of dilute sulfuric acid can identify three black powders; therefore a is correct; b. Although iron powder can react with copper sulfate solution to obtain red copper and light green ferrous sulfate solution, because charcoal and copper oxide cannot react with copper sulfate solution, the use of copper sulfate solution can not identify three black powders: charcoal, copper oxide and iron powder; Therefore b is incorrect; c. Because charcoal, copper oxide and iron powder cannot react with sodium hydroxide solution, and there is no obvious change in the three black powders when placed in sodium hydroxide solution, sodium hydroxide solution cannot be used to identify the three substances; Therefore c is incorrect; d. Because charcoal, copper oxide and iron powder cannot react with water, there is no obvious change in the three black powders when put into water, so water cannot be used to identify the three substances; Therefore d is incorrect; Therefore, choose a comment: When identifying a substance, the selected reagent or method must be able to appear significantly different experimental phenomena, so that the reagent or method can achieve the identification of the substance

a. Although iron powder can be reacted with copper sulfate solution to obtain red copper and light green ferrous sulfate solution, because charcoal and copper oxide cannot react with copper sulfate solution, the use of copper sulfate solution can not identify charcoal, copper oxide, iron powder three black powders, so A is incorrect;

B. Because charcoal, copper oxide, and iron powder cannot react with water, and there is no obvious change in the three black powders when they are put into water, so B is incorrect;

c. Because charcoal, copper oxide and iron powder cannot react with sodium hydroxide solution, there is no obvious change in the three black powders in sodium hydroxide solution, so D is incorrect;

d. Put charcoal, copper oxide and iron powder into dilute sulfuric acid, and there is no obvious change for charcoal; The black solid dissolves, the solution turns blue, and the black solid is copper oxide; The black solid is dissolved, the solution is light green and bubbles are generated, and the solid is iron powder Therefore, the use of dilute sulfuric acid can identify three black powders, so d is correct

Therefore, choose D

a. Although iron powder can be reacted with copper sulfate solution to obtain red copper and light green ferrous sulfate solution, because Chi Dan is charcoal and copper oxide cannot react with copper sulfate solution, therefore, the use of copper sulfate solution can not identify charcoal, copper oxide, iron powder three black powders; therefore a is incorrect;

b. Because charcoal, copper oxide and iron powder cannot react with water, there is no obvious change in the three black powders when they are put into water, so water cannot be used to identify the three substances; Therefore b is incorrect;

c. Put charcoal, copper oxide, and iron powder into dilute sulfuric acid, and charcoal is the one that has no obvious clear change; The black solid dissolves, the solution turns blue, and the black solid is copper oxide; The black solid is dissolved, the solution is light green and bubbles are generated, and the solid is iron powder; Therefore, the use of dilute sulfuric acid can identify three black powders; Therefore c is correct;

d. Because charcoal, copper oxide and iron powder can not react with sodium hydroxide solution, there is no obvious change in the three black powders when they are put into sodium hydroxide solution, so sodium hydroxide solution cannot be used to identify the three substances; Therefore d is incorrect;

Therefore, C