Iron replaces silver Fe 2Ag Fe2 2Ag

Of course, the metallicity of iron is stronger than that of silver, in fact, the essence is that Fe is a relatively strong reducing agent, Ag+ is an oxidizing agent, they will react together, Fe will be oxidized to Fe2+, and Ag+ will be reduced to elemental Ag

Metallic activity sequence table.

Junior high) potassium, calcium, sodium, magnesium, aluminum, zinc, iron, tin, lead, hydrogen, copper, mercury, silver, platinum.

k ca na mg al zn fe sn pb (h) cu hg ag pt au

High school) potassium, calcium, sodium, magnesium, aluminum, manganese, zinc, chromium, iron, nickel, tin, lead, hydrogen; Copper, mercury, silver, platinum.

k ca na mg al mn zn cr fe ni sn pb (h) cu hg ag pt au

1) For metal reducing agents, the reducibility of metal elements is generally consistent with the order of metal activity, that is, the more metal is located behind, the less likely it is to lose electrons, and the weaker the reducibility.

Reducibility: K>Ca>Na>Mg> Al>Mn>Zn>Cr>Fe>Ni>Sn>Pb>(H)>Cu>Ag>Hg>PT>au

2) The order of oxidation of metal cations.

k+

Because iron is ranked before h and ag in the order of metal activity, it is more active than ag, so silver can be replaced in solution.

Because iron is more metallic than silver.

(i) From the equation 2AG+(AQ)+FE(S)=FE2+(AQ)+2AG(S), it can be seen that AG+ is reduced in the reaction, which should be a positive reaction, then the electrolyte solution is silver nitrate solution, FE is oxidized, it should be the negative electrode reaction of the galvanic battery, X is Fe in the device diagram, Y is silver nitrate solution, 1) the material of electrode X is Fe; The electrolyte solution Y is the AGNO3 solution; So the answer is: fe; agno3 solution;

2) X is Fe, Fe electron loss is oxidized to form ferrous ions, and its electrolysis reaction is: Fe-2E-=Fe2+, so the answer is: Fe-2E-=Fe2+;

3) The cations in the solution move to the positive electrode, so the direction of the cations in the salt bridge is to move to y; So the answer is: move to y;

ii) (1) The composition of rust is Fe2O3?XH2O, can react with hydrochloric acid to form ferric chloride and water, ferric chloride is oxidizing, can undergo redox reaction with iron to form ferrous chloride, the reaction equation is 2FeCl3+Fe 3FeCl2, so the answer is: 2FeCl3+Fe 3FeCl2;

5) When copper is plated on iron, copper is used as the anode to connect to the positive electrode of the galvanic battery, and iron is used as the cathode to connect to the negative electrode of the galvanic battery, so a is copper, b is iron, and the copper ions on the iron electrode obtain electrons to generate copper element, and the electrode reaction formula is Cu2++2E- Cu, so the answer is: copper; cu2++2e-═cu；

During electroplating, the loss of electrons of the metal on the anode leads to a decrease in the mass of the metal, and the precipitation of the metal on the cathode leads to an increase in the mass, and half of the difference in the mass of the two poles after electroplating is the mass of copper precipitated on the cathode, so the mass of copper precipitated on the cathode =

2=, the amount of matter transferring electrons =

64g/mol

mol, so the answer is:

c Analysis: Among the reactants, iron is an element, and silver nitrate is a compound; Among the products, silver is an elemental substance, and ferrous nitrate is a compound; This reaction belongs to the displacement reaction

Solution: In Fe+2AGnO3 =2AG+Fe(NO3)2, both the reactant and the product are a kind of elemental and a compound, which belongs to the displacement reaction

Therefore, C

A The device can be an electrolytic cell, A is the cathode, B is the anode, and can also be a galvanic battery, A is the positive electrode, B is the positive electrode, so A is wrong;

b When the device is an electrolytic cell, a and b can be both ferroelectrode materials, so b is correct;

c From the A pole, it can be seen that the electrolyte solution is silver nitrate, so C is wrong;

The addition of the reaction formulas of D A and B can obtain Fe+2AG+=Fe2++2AG, which is the total reaction formula, so D is correct

So choose AC

Fe plus Ag+ is equal to Fe2+ plus Ag How did the divalent Fe ion come about.

When Fe elements are replaced, positive bivalent ferrous salts are generated.

Fe + 2 agno3 == Fe (NO3) 2 + 2 ag ion equation: Fe + 2ag ion == Fe ion + 2agag ion: Ag+

Fe ion: Fe2+

A. The positive electrode is Ag as the material, then electrode A uses iron as the negative electrode, the electrolyte solution is AgNO3 solution, when electrolyzing NaCl solution, C is the cathode of the electrolytic cell, and the reaction that occurs is 2H++2E-H2, or 2H2O+2E-H2 +2OH-, and phenolphthalein is added to turn red, so A is correct;

B In the galvanic cell, a electrode is the negative electrode of the galvanic cell, the reaction that occurs is: Fe-2E-=Fe2+, the positive electrode is Ag as the material, the electrolyte solution is AgnO3 solution, and the reaction that occurs is: Ag++E-=Ag, so B is correct;

c When precipitated, n(ag).

108mol, transfer electrons, according to 2H2O+2E- H2+2Oh-, it can be judged that N(Oh-) then C(Oh-).

1mol L, so the pH of the solution is 14, which is 2 times that before the reaction, so C is correct;

D A is the negative electrode of the galvanic battery, which undergoes oxidation reaction, and C electrode is the cathode of the electrolytic cell, which undergoes a reduction reaction, so D is wrong;

Therefore, choose D

a. The silver row is behind the hydrogen, the hydrogen cannot be replaced, and the reaction cannot occur, so A is wrong;

b. The essence of the reaction between sulfuric acid and barium hydroxide is: 2H+

2oh-so4

ba2+baso4

2h2o, so b is wrong;

c. Carbonic acid is easily decomposed into water and carbon dioxide, which should be: CaCO3+2H+

Ca2+H2O+CO2, so C is wrong;

d. Hydrochloric acid can dissolve alkaline oxides to obtain the corresponding salt and water, so D is correct and D is selected

fe+2ag+==fe2++2ag

Add excess iron, and then add an appropriate amount of dilute sulfuric acid, iron reacts to form ferrous ions, silver precipitates, and filtration gives silver.

cl2+2naoh==nacl+naclo+h2o