Chemical Redox Reaction Problems 20

a) Reduction reaction: Cl2 + 2E- = 2Cl- oxidation reaction: 2br- -2e- = br2 ion equation:

Cl2 + 2br- = 2Cl- +br2b) Reduction reaction: mnO4- +8H+ +5E- = Mn2+ +4H2O

Oxidation reaction: 5Fe2+ -5E- = 5Fe3+ ion equation: Mno4- +5Fe2+ +8H+ = Mn2+ +5Fe3+ 4H2O

Supplement: The potassium in KMno4 is K+, which has only one +1 valence; Also, you can directly call Feso4 ferrous sulfate, instead of calling it iron sulfate and add II to the table later.

a) Reaction of chlorine with aqueous solution of potassium bromide.

Reduction semi-equation: cl2 +2e- =2cl- oxidation semi-equation: 2i- -2e- =2i-

Ionic equation: 2i- +cl2 =2cl- +i2b) acidified potassium permanganate aqueous solution with iron(ii).

The ferric (ii) sulfate here refers to ferrous sulphate.

Reduction semi-equation: mno4- +5e- +8h+ =mn2+ +4h2o

Oxidation Half Equation: Fe2+ -E ==Fe3+ Ion Equation: 5Fe2+ +MNO4- +8H+ == 5Fe3+ +Mn2+ +4H2O

Oxidation-reduction reaction is a type of reaction in which the oxidation number of an element changes before and after a chemical reaction. [1] The essence of a redox reaction is the gain or loss of electrons or the shift of shared electron pairs. Redox reaction is one of the three basic reactions in chemical reactions (the other two are (Lewis) acid-base reactions and free radical reactions.

2]。Combustion, respiration, photosynthesis, chemical batteries in production and life, metal smelting, rocket launches, etc. are all closely related to redox reactions in nature. The study of redox reactions is of great significance to the progress of mankind.

1. Reaction type:

Oxidation reaction: A reaction in which the valency of the elements contained in a substance increases.

Reduction reaction: A reaction in which the valency of the elements contained in a substance decreases.

Redox reaction: There is a reaction in which the valency of the elements increases and decreases.

2. Reactants:

Oxidant: A substance that gives electrons in a reaction.

Reducing agent: A substance that loses electrons in a reaction.

3. Product: Oxidation product: the product obtained after the loss of electrons is oxidized.

Reduction product: The product obtained after the electrons are reduced.

4. Material properties:

Oxidation: The properties of the electrons exhibited by the oxidizing agent.

Reducibility: The electron-losing property exhibited by the reducing agent.

Oxidation-reduction reaction is a type of reaction in which the oxidation number of an element changes before and after a chemical reaction. The essence of a redox reaction is the gain or loss of electrons or the shift of shared electron pairs.

In the reaction, the substances that undergo oxidation reactions, called reducing agents, produce oxidation products; A substance that undergoes a reduction reaction, called an oxidant, produces a reduction product. Oxidation products are oxidizing but weaker than oxidants; The reducing product is reducing, but weaker than the reducing agent.

Common Oxidants:

1. Potassium permanganate (KMNO4).

Potassium permanganate has strong oxidation, and can oxidize alkyls, aldecordehydes, and aryl groups of primary alcohols, aldehydes, and aromatic ring side chains into acids.

2. Manganese dioxide (mnO2).

Manganese dioxide is a milder oxidizing agent that oxidizes methyl groups in the side chains of aromatic rings to aldehydes.

1. Reaction type:

Oxidation reaction: A reaction in which the valency of the elements contained in a substance increases.

Reduction reaction: A reaction in which the valency of the elements contained in a substance decreases.

Redox reaction: There is a reaction in which the valency of the elements increases and decreases.

2. Reactants:

Oxidant: A substance that gives electrons in a reaction.

Reducing agent: A substance that loses electrons in a reaction.

3. Product: Oxidation product: the product obtained after the loss of electrons is oxidized.

Reduction product: The product obtained after the electrons are reduced.

4. Material properties:

Oxidizing: The properties of the electrons exhibited by the oxidizing agent.

Reducibility: The electron-losing property exhibited by the reducing agent.

This problem uses the extreme value method to find:

Suppose that all the gases produced are no, and the amount of matter of no is x, which is obtained according to the conservation of copper atoms

The amount of copper sulfide = the amount of copper oxide = m m = equal according to the total number of electrons gained and lost:

x*[(5)-(2)]=

x=then the volume of the standard state to generate no v=nvm=

Suppose that all the gases produced are NO2, and the amount of matter of NO2 is y, which is obtained according to the conservation of copper atoms

The amount of copper sulfide = the amount of copper oxide = m m = equal according to the total number of electrons gained and lost:

x*[(5)-(4)]=

x=then the volume of NO2 generated by the standard condition v=nvm=

If the above gas is a mixture of no and no2, and the volume ratio is 1 1, n(cuo)=12 80=;

If all are cus, lose electrons n1(e)=; v=；

If all Cu2S is lost, electrons N2(E)=; v=

d1) naclo3

When SO2 is oxidized, Naclo3 is reduced and reduced, and the CL oxidation state in the generated species is lower than that of Naclo3 (+5).

2) naclo2

When Cl2 is reduced, Naclo2 is oxidized and the price increases, and the Cl oxidation state in the generating species is higher than that of NaClO2 (+3).

Then the CL oxidation state of the common species is +4, and D is selected

I do it by valence change of Cl and choose D