The following particles are only reducing, and the following groups of particles are only reducing

Reducibility means that the particle is able to obtain electrons, that is, the valency can be reduced. The ferrous ions in a are +2 valence, and the elemental iron is 0 valence, so it is reducible; In b, S2- is the lowest valence state of sulfur, which can not be reduced, so there is no reduction; The chlorine element in C is +1 valence, because the chlorine element has a -1 valence (as in HCl), so it is reducible; D is sulfur element, which is reducible, and the reason is shown in option B.

B. Ferrous ions can be reduced to 0-valent elemental iron, which is a manifestation of the oxidation of ferrous ions The chlorine element of hypochlorite can be reduced to -1 valence chloride ions, which is also a manifestation of oxidation Elemental sulfur can be turned into -2-valent S2-, which is also a manifestation of oxidation S2- is the lowest valence state of sulfur, which can only be changed to ** state, reflecting the reduction Therefore, the answer is B

b,s2- is in the lowest valence state, only reductive. The others are in the intermediate valence state, which is both reducing and oxidizing.

A, the rise can be reduced, both oxidizing and reducing B, the lowest price is only reducing, so choose B C, Cl in HCL is +1 valence, which is also an intermediate valence state, both oxidizing and reducing D, S is 0 valence, which is also an intermediate valence.

Reducibility is the one that can increase the valency, on the contrary, oxidation is the one that the valency can be reduced, and the above 4 kinds of particles S2- can only be increased, not decreased, so it is Tale.

b,s at the lowest price The element at the lowest value is only reductive.

Only reductivity means that it is the lowest valence, so choose b

CO has both oxidizing and reducing properties, carbon + 2 valence, and the valency can be both increased and decreased.

The carbon valency of CO+cuo--CO2 increases.

CO+ H2 = C+ H2O with reduced carbonization valency.

Fluorine is the boss and has the strongest oxidation.

One of the manifestations of C reduction is that H+ in A, where the valency can be increased in the chemical reaction, H is (+1) is the most, and it can only be reduced, showing oxidation;

In b, SO2,S is (+4) and can be increased to (+6); It can also be reduced (0 valence, -2), b is both oxidizing and reducing;

In c, cl-, and cl are (-1), which is the lowest valence state and can only rise, which is reductive;

Fe2+, Fe is (+2) and can be increased to (+3); It can also be reduced (0 valence) d, which is both oxidizing and reducing.

Only oxidizing is the one in which the valency is in the most ** state.

price, the lowest price, only reductive.

The intermediate valence state, which is both oxidizing and reducing.

The most **, only oxidizing.

valence, intermediate valence, is both oxidizing and reducing. (h has -1 valence).

When the valency is lowest, there is only reductivity, so the answer is c

It is located in the seventh main family, so the minimum negative price is -1 price. At this time, Cl- has reached the lowest negative price, so the valence can only increase. The valency increases, electrons are lost, oxidation reactions occur, and they are used as reducing agents and contain reducing properties, so C is selected

It has both oxidation resistance and reductiveness, indicating that it is an intermediate valence.

Because the most ** is only oxidizing, and the lowest price is only reducing.

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Question B analysis: particles with valency in the intermediate valence state are both oxidizing and reducing, B is correct; Hydrogen ions and copper ions are only oxidizing, and metal aluminum is only reducing, and the answer is b.

Comments: This question is an examination of basic test questions, and it is also a common test point in the college entrance examination. The test questions are based on a strong foundation, mainly to test students' familiarity with oxidation and reduction judgments, which is conducive to cultivating students' logical reasoning ability and improving students' ability to flexibly use basic knowledge to solve practical problems.

A and C sulfur and hydrogen reaction systems have oxidation, and the reaction with oxygen reflects their reducibility;

Cl2+H2O=HCl+HClThis reaction reflects both its reducing and oxidizing properties.

Choosing a sulfur element can not only gain electrons to become -2-valent S2- (oxidizing), but also lose electrons to become +4-valent sulfur (reducing).

For example: s + H2 = = catalyst = = H2S (reflects oxidation).

S +O2==Ignition ==SO2 (reflects reductivity).

The valency of ac is in the intermediate valence state, which is both oxidizing and reducing.

Oxidation: 1. Strong non-metallic single-brigade bucket quality: F2, Cl2, Br2, I2, O2, O3, etc.;

2. Valence compounds in valence elements: KCLO3, KMnO4, Fe3+ salt, K2Cr2O7, concentrated H2SO4, HNO3, solid laughing lead nitrate, etc.;

3. Substances that can ionize H+: dilute H2SO4, dilute HCl, etc.;

4. Others: HCl, MNO2, Na2O2, NO2, H2O2, NaHSO4, silver ammonia solution, new Cu(OH)2, bleaching powder, etc.

Reducing agent: 1. Elemental elements with strong metallic properties: K, NA, MG, AL, FE, ZN, etc.;

2. Some non-metallic elements: H2, C, Si, etc.;

3. Some low-valence compounds in valence elements: CO, H2S and sulfides, Fe2+ salts, Fe(OH)2, HBR, Hi and salts, concentrated HCl, etc.;

4. Others: elemental S, SN2+ salt, SO2 and sulfite, etc.

The order of oxidation of halogen elements is: F2 Cl2 B2 I2, so the reducing order of ions is: F- Cl- br- I-

Therefore, choose D

The valency of Al and Cl- is the lowest, so there is only reduction, and the valency of H+ is the most important, so there is only oxidation, and the valency of Fe2+ is an intermediate valence state, so it has both oxidation and reduction, so C is chosen